© Doc Brown's KS3 Chemistry Quiz 7F "Important chemical concepts, definitions, types of reaction" click [?] (re-edit 03/01/2023)

Which gas is a naturally occurring fuel? [7f-4]
1. hydrogen
2. oxygen
3. carbon dioxide
4. methane
In a chemistry experiment, which word means what you start with? [7f-5]
1. reactant
2. product
3. equation
4. evaluation
In a chemistry experiment, which word means what you end up with? [7f-6]
1. reactant
2. product
3. equation
4. evaluation
In a chemistry experiment, which word represents the overall change? [7f-7]
1. reactant
2. product
3. equation
4. evaluation
In a chemistry preparation experiment, which word means how well it has gone? [7f-8]
1. reactant
2. product
3. equation
4. evaluation
A variety of observations can indicate whether or not a chemical reaction is happening when chemicals are mixed. Which of the following is most likely to indicate a chemical change has happened, and new substances have been formed? [7f-9]
1. the colour changes
2. no gas bubbles form
3. the mixture doesn't change temperature
4. a clear solution is formed
A variety of observations can indicate whether or not a chemical reaction is happening when chemicals are mixed. Which of the following is most likely to indicate a chemical change has happened, and new substances have been formed? [7f-10]
1. there is no colour change
2. gas bubbles form
3. the mixture doesn't change temperature
4. no precipitate forms (a solid forming out of mixing solutions)
A variety of observations can indicate whether or not a chemical reaction is happening when chemicals are mixed. Which of the following is most likely to indicate a chemical change has happened, and new substances have been formed? [7f-11]
1. there is no colour change
2. no gas bubbles form
3. the mixture changes temperature
4. a clear solution is formed
A variety of observations can indicate whether or not a chemical reaction is happening when chemicals are mixed. Which of the following is most likely to indicate a chemical change has happened, and new substances have been formed? [7f-12]
1. there is no colour change
2. no gas bubbles form
3. the temperature stays the same
4. a precipitate forms (a solid forming out of mixing solutions)
A variety of observations can indicate whether or not a chemical reaction is happening when chemicals are mixed. Which of the following is most likely to indicate a chemical change when a fuel burns? [7f-15]
1. there is a coloured flame
2. no gas bubbles form
3. the mixture changes temperature
4. a clear solution is formed
A variety of observations can indicate whether or not a chemical reaction is happening when chemicals are mixed. Which of the following is most likely to indicate a chemical change when carbon dioxide is passed into limewater? [7f-16]
1. there is no colour change
2. no gas bubbles form
3. the temperature stays the same
4. a precipitate forms (a solid forming out of mixing solutions)
Which of the following best describes what is formed when methane reacts with oxygen? [7f-17]
1. carbon dioxide + water
2. salt + hydrogen
3. salt + water + carbon dioxide
4. an oxide
Which of the following is always formed when an element reacts with oxygen? [7f-20]
1. carbon dioxide + water
2. salt + hydrogen
3. salt + water + carbon dioxide
4. an oxide
Which of the following burns to form the acidic gas sulfur dioxide? [7f-32]
1. magnesium sulfate
2. sulfuric acid
3. sulfur trioxide
4. sulfur
Which is TRUE about chemical reaction changes? [7f-33]
1. new substances are always formed
2. the change is easily reversed
3. sometimes new substances are formed
4. there is rarely visible evidence of the change
Which is TRUE about chemical reaction changes? [7f-34]
1. new substances are sometimes formed
2. the change is not easily reversed
3. no new substances are formed
4. there is rarely visible evidence of the change
Which is TRUE about physical changes but not chemical changes? [7f-35]
1. new substances are sometimes formed
2. the change is not easily reversed
3. no new substances are formed
4. there is rarely visible evidence of the change
Which is TRUE about physical changes but not chemical changes? [7f-36]
1. new substances are sometimes formed
2. there is rarely visible evidence of the change
3. new substances are always formed
4. the change is easily reversed
Which of the following is a physical change and not a chemical change? [7f-37]
1. melting gold to cast a statue in a mould
2. shiny steel changing to brown rust powder
3. burning petrol to form liquid water and carbon dioxide gas
4. zinc dissolving in hydrochloric acid
Which of the following is a physical change and not a chemical change? [7f-38]
1. shiny steel changing to brown rust powder
2. cast iron solidifying from a blast furnace
3. burning petrol to form liquid water and carbon dioxide gas
4. zinc dissolving in hydrochloric acid
Which of the following is a physical change and not a chemical change? [7f-39]
1. mixing acid with alkali causes a temperature rise
2. burning wax to form liquid water and carbon dioxide gas
3. steam condensing from boiling water
4. zinc dissolving in hydrochloric acid
Which of the following is a physical change and not a chemical change? [7f-40]
1. mixing acid with alkali causes a temperature rise
2. burning wax to form liquid water and carbon dioxide gas
3. zinc dissolving in hydrochloric acid
4. salt crystals forming from evaporating sea water
Which of the following is a physical change and not a chemical change? [7f-41]
1. petrol evaporating from a garage floor
2. burning wax to form liquid water and carbon dioxide gas
3. zinc dissolving in hydrochloric acid
4. marble chips dissolving in acid producing fizzing
Which of the following is a physical change and not a chemical change? [7f-42]
1. heated green copper carbonate turns it black
2. whisky condensing in a distillery
3. zinc dissolving in hydrochloric acid
4. marble chips dissolving in acid producing fizzing
Which of the following is a physical change and not a chemical change? [7f-43]
1. heated green copper carbonate turns it black
2. magnesium dissolving in sulfuric acid
3. sugar dissolving in water
4. marble chips dissolving in acid produces fizzing
Which of the following is a physical change and not a chemical change? [7f-44]
1. heated green copper carbonate turns it black
2. magnesium dissolving in sulfuric acid
3. adding lemon juice to solid bicarbonate of soda
4. freezing banana skins in liquid nitrogen
Which of the following represents a chemical change and not a physical change? [7f-45]
1. mixing acid with alkali causes a temperature rise
2. casting iron from a blast furnace
3. distilling whisky from fermented barley
4. freezing animal tissue in liquid nitrogen
Which of the following represents a chemical change and not a physical change? [7f-46]
1. casting iron from a blast furnace
2. brown powder forming on iron gates
3. distilling whisky from fermented barley
4. freezing animal tissue in liquid nitrogen
Which of the following represents a chemical change and not a physical change? [7f-47]
1. petrol evaporating from the fuel tank
2. sugar dissolving in vinegar
3. burning wax in a candle
4. crystallising blue copper sulfate crystals from a heated solution
Which of the following represents a chemical change and not a physical change? [7f-48]
1. petrol evaporating from the fuel tank
2. sugar dissolving in vinegar
3. crystallising blue copper sulfate crystals from a heated solution
4. dissolving zinc in hydrochloric acid
Which of the following represents a chemical change and not a physical change? [7f-49]
1. dissolving marble chips in acid
2. condensing pure water from a distillation
3. melting brass to cast a door knob
4. boiling water to drive out dissolved gases
Which of the following represents a chemical change and not a physical change? [7f-50]
1. condensing pure water from a distillation
2. heating green copper carbonate makes a black powder
3. melting brass to cast a door knob
4. boiling water to drive out dissolved gases
Which of the following represents a chemical change and not a physical change? [7f-51]
1. water freezing into hexagonal crystals
2. basalt crystals forming from molten lava
3. dissolving bicarbonate of soda in lemon juice
4. lemonade fizzing when the bottle top is taken off
Which of the following represents a chemical change and not a physical change? [7f-52]
1. water freezing into hexagonal star shaped crystals
2. basalt crystals forming from molten lava
3. lemonade fizzing when the bottle top is taken off
4. magnesium fizzing in sulfuric acid
Which is TRUE about burning fossil fuels? [7f-53]
1. most fuels contain a high percentage of carbon
2. the fuel reacts with nitrogen
3. little heat energy is released
4. clean fuels burn with a yellow flame
Which is TRUE about burning fossil fuels? [7f-54]
1. most fuels contain a low percentage of carbon
2. the fuel reacts with oxygen
3. little heat energy is released
4. clean fuels burn with a yellow flame
Which is TRUE about burning fossil fuels? [7f-55]
1. most fossil fuels contain a low percentage of carbon
2. the fuel reacts with nitrogen
3. much heat energy is released
4. clean fuels burn with a yellow flame
Which is TRUE about burning fossil fuels? [7f-56]
1. most fuels contain a low percentage of carbon
2. the fuel reacts with nitrogen
3. little heat energy is released
4. clean fuels burn with a pale blue flame
Which of the following does NOT indicate a chemical change is happening when a candle burns? [7f-64]
1. light is given out from the flame
2. heat is given out by the flame
3. the candle goes out within a minute if a beaker is placed over it.
4. the heat from the flame melts the wax
Which of the following is only a physical change? [7f-67]
1. marble chips fizz with acid
2. magnesium burns brightly when heated in air
3. when zinc oxide is heated it turns yellow, on cooling it becomes white
4. heating green copper carbonate powder turns it black
The diagram shows an experiment to investigate the products of burning a hydrocarbon molecule like candle wax. What are the condensed colourless drops formed called? [7f-68]
1. carbon dioxide
2. oxygen
3. methane
4. water
The diagram shows an experiment to investigate the products of burning a hydrocarbon molecule like candle wax. If limewater is in the left-hand U, what is formed that causes the milky white precipitate? [7f-69]
1. carbon dioxide
2. condensed wax vapour
3. methane
4. water
Which of the following could be described as a reversible change? [7f-70]
1. marble chips fizz with acid
2. when zinc oxide is heated it turns yellow, on cooling it becomes white
3. magnesium burns brightly when heated in air
4. heating green copper carbonate powder turns it black
Chemical changes make new materials and tend not to be readily reversed. Physical changes do not make new materials and tend to be readily reversed. Which of the following is a chemical change? [7f-71]
1. the evaporation of a rain puddle
2. ice cracking a milk bottle
3. frying an egg
4. melting butter
Chemical changes make new materials and tend not to be readily reversed. Physical changes do not make new materials and tend to be readily reversed. Which of the following is a chemical change? [7f-72]
1. condensation forming on a window
2. ice cracking a milk bottle
3. melting butter
4. igniting a gas fire
Chemical changes make new materials and tend not to be readily reversed. Physical changes do not make new materials and tend to be readily reversed. Which of the following is a chemical change? [7f-73]
1. baking pottery clay in a kiln
2. ice cracking a milk bottle
3. melting butter
4. the evaporation of a rain puddle
Chemical changes make new materials and tend not to be readily reversed. Physical changes do not make new materials and tend to be readily reversed. Which of the following is a physical change? [7f-74]
1. baking pottery clay in a kiln
2. ice cracking a milk bottle
3. treating a bee sting
4. milk turning sour
Chemical changes make new materials and tend not to be readily reversed. Physical changes do not make new materials and tend to be readily reversed. Which of the following is a physical change? [7f-75]
1. baking pottery clay in a kiln
2. treating a wasp sting
3. melting butter
4. milk turning sour
Chemical changes make new materials and tend not to be readily reversed. Physical changes do not make new materials and tend to be readily reversed. Which of the following is a physical change? [7f-75]
1. baking pottery clay in a kiln
2. treating a wasp sting
3. wood rotting
4. condensation forming on windows
Which statement is TRUE when the yellow solid sulfur is heated in air and then burns to form a colourless gas? [7f-82]
1. it is a physical change
2. the change is not easily reversed
3. the reaction takes in heat energy
4. the product is called sulfuric oxide
Which statement is TRUE when the yellow solid sulfur is heated in air and then burns to form a colourless gas? [7f-83]
1. it is a physical change
2. the change is easily reversed
3. the reaction gives out heat energy
4. the product is called sulfuric oxide
The diagram shows a simple candle burning experiment and a graph of the results. What was the volume of the beaker that probably gave the least accurate result? [7f-84]
1. 100 cm³
2. 400 cm³
3. 800 cm³
4. 200 cm³
The diagram shows a simple candle burning experiment and a graph of the results. What volume of beaker would probably allow the candle to burn for 40 seconds? [7f-85]
1. 500 cm³
2. 450 cm³
3. 550 cm³
4. 350 cm³
The diagram shows a simple candle burning experiment and a graph of the results. What would be a reasonable estimate of the candle burning time if a 1500 cm³ beaker was used in the experiment? [7f-86]
1. 110 seconds
2. 120 seconds
3. 130 seconds
4. 140 seconds
The diagram shows a simple candle burning experiment and a graph of the results. During the experiment, what change happens to the gases in the beaker? [7f-87]
1. the oxygen decreases and the carbon dioxide decreases
2. the oxygen increases and the carbon dioxide increases
3. the oxygen decreases and the carbon dioxide increases
4. the oxygen increases and the carbon dioxide decreases
What is the formula of the molecule? [8f-9]
1. C₂H₆O
2. ₂C₆HO
3. C₃H₆
4. C₆H₂O
What is the formula of the molecule? [8f-10]
1. C₅H₆I₂
2. C₃H₆Cl₂
3. C₆H₃Cl₂
4. C₂H₆Cl₃
What is the formula of the molecule? [8f-11]
1. C₈H₃
2. ₃C₈H
3. C₃H₈
4. C₃H₆
What is the formula of the molecule? [8f-12]
1. C₂H₆O₃
2. ₃C₆H₂O
3. C₅H₆O
4. C₃H₆O₂
Silvery grey iron filings are added to yellow sulphur powder in a test tube, a mixture of two reactants. The contents of the test tube were strongly heated until they glowed red without further heating to form a dark grey dull solid. Which statement is TRUE about the contents of the test tube in the experiment? [8f-33]
1. at the start they are a mixture
2. at the end they are a mixture
3. at the start they cannot be separated with a magnet
4. at the end they can be separated with a magnet
Silvery grey iron filings are added to yellow sulphur powder in a test tube, a mixture of two reactants. The contents of the test tube were strongly heated until they glowed red without further heating to form a dark grey dull solid. Which statement is TRUE about the contents of the test tube in the experiment? [8f-34]
1. at the start they are a compound
2. at the end they are a compound
3. at the start they cannot be separated with a magnet
4. at the end they can be separated with a magnet
Silvery grey iron filings are added to yellow sulphur powder in a test tube, a mixture of two reactants. The contents of the test tube were strongly heated until they glowed red without further heating to form a dark grey dull solid. Which statement is TRUE about the contents of the test tube in the experiment? [8f-35]
1. at the start they are a compound
2. at the end they are a mixture
3. at the start they can be separated with a magnet
4. at the end they can be separated with a magnet
Silvery grey iron filings are added to yellow sulphur powder in a test tube, a mixture of two reactants. The contents of the test tube were strongly heated until they glowed red without further heating to form a dark grey dull solid. Which statement is TRUE about the contents of the test tube in the experiment? [8f-36]
1. at the start they are a compound
2. at the end they are a mixture
3. at the start they cannot be separated with a magnet
4. at the end they cannot be separated with a magnet
Silvery grey iron filings are added to yellow sulphur powder in a test tube, a mixture of two reactants. The contents of the test tube were strongly heated until they glowed red without further heating to form a dark grey dull solid. Which statement is TRUE about the contents of the test tube in the experiment? [8f-37]
1. the colour change suggests a chemical reaction has happened overall
2. FeS describes them at the start, Fe + S describes them at the end
3. at the start, acid will act on the iron forming hydrogen and the same gas is formed with acid with the dark-grey solid product
4. the red glow without heating shows overall a physical change has happened to the mixture when cool
Silvery grey iron filings are added to yellow sulphur powder in a test tube, a mixture of two reactants. The contents of the test tube were strongly heated until they glowed red without further heating to form a dark grey dull solid. Which statement is TRUE about the contents of the test tube in the experiment? [8f-38]
1. the colour change suggests a physical change has happened overall
2. Fe + S describes them at the start, FeS describes them at the end
3. at the start, acid will act on the iron forming hydrogen and the same gas is formed with acid with the dark-grey solid product
4. the red glow without heating shows overall a physical change has happened to the mixture when cool
Silvery grey iron filings are added to yellow sulphur powder in a test tube, a mixture of two reactants. The contents of the test tube were strongly heated until they glowed red without further heating to form a dark grey dull solid. Which statement is TRUE about the contents of the test tube in the experiment? [8f-39]
1. the colour change suggests a physical change has happened overall
2. FeS describes them at the start, Fe + S describes them at the end
3. at the start, acid will act on the iron forming hydrogen and hydrogen sulphide gas is formed with acid and the dark-grey solid product
4. the red glow without heating shows overall a physical change has happened to the mixture when cool
Silvery grey iron filings are added to yellow sulphur powder in a test tube, a mixture of two reactants. The contents of the test tube were strongly heated until they glowed red without further heating to form a dark grey dull solid. Which statement is TRUE about the contents of the test tube in the experiment? [8f-40]
1. the colour change suggests a physical change has happened overall
2. FeS describes them at the start, Fe + S describes them at the end
3. at the start, acid will act on the iron forming hydrogen and the same gas is formed with acid and the dark-grey solid product
4. the red glow without heating suggests overall a chemical change has happened to the mixture when cool
Which particle is a compound made up of three elements? [8f-49]
1. 8
2. 2
3. 4
4. 7
Which particle is a compound made up of three elements? [8f-50]
1. 2
2. 9
3. 4
4. 7
Which particle is an element made up of single atoms? [8f-51]
1. 1
2. 6
3. 3
4. 5
Which particle is a compound made up of two elements? [8f-52]
1. 3
2. 5
3. 6
4. 1
Which particle is a compound made up of two elements? [8f-53]
1. 7
2. 8
3. 6
4. 3
Which particle is a molecule made of 4 atoms? [8f-54]
1. 7
2. 6
3. 8
4. 2
Which particle is formed when two different colourless gases chemically combine? [8f-55]
1. 7
2. 6
3. 4
4. 2
Which particle is formed when a black solid and a colourless gas are chemically combined? [8f-56]
1. 9
2. 6
3. 4
4. 2
Which of the following is a 'combustion reaction'? [rt-1]
1. CH_4(g) + 2O_2(g) ==> CO_2(g) + 2H₂O_(l)
2. NaOH_(aq) + HCl_(aq) ==> NaCl_(aq) + H₂O_(l)
3. CaCO_3(s) ==> CaO_(s) + CO_2(g)
4. C₆H₁₂O_6(aq) ==> 2C₂H₅OH_(aq) + 2CO_2(g)
Which of the following is a 'neutralisation reaction'? [7f]
1. CH_4(g) + 2O_2(g) ==> CO_2(g) + 2H₂O_(l)
2. NaOH_(aq) + HCl_(aq) ==> NaCl_(aq) + H₂O_(l)
3. CaCO_3(s) ==> CaO_(s) + CO_2(g)
4. C₆H₁₂O_6(aq) ==> 2C₂H₅OH_(aq) + 2CO_2(g)
Which of the following is a 'thermal decomposition' reaction? [rt-3]
1. CH_4(g) + 2O_2(g) ==> CO_2(g) + 2H₂O_(l)
2. NaOH_(aq) + HCl_(aq) ==> NaCl_(aq) + H₂O_(l)
3. CaCO_3(s) ==> CaO_(s) + CO_2(g)
4. C₆H₁₂O_6(aq) ==> 2C₂H₅OH_(aq) + 2CO_2(g)
Which of the following is a 'combustion' reaction? [rt-5]
1. methane + oxygen => carbon dioxide + water
2. sodium hydroxide + hydrochloric acid => sodium chloride + water
3. calcium carbonate => calcium oxide + carbon dioxide
4. glucose => ethanol + carbon dioxide
Which of the following is a 'neutralisation' reaction? [rt-6]
1. methane + oxygen => carbon dioxide + water
2. sodium hydroxide + hydrochloric acid => sodium chloride + water
3. calcium carbonate => calcium oxide + carbon dioxide
4. glucose => ethanol + carbon dioxide
Which of the following is a 'thermal decomposition' reaction? [rt-7]
1. methane + oxygen => carbon dioxide + water
2. sodium hydroxide + hydrochloric acid => sodium chloride + water
3. calcium carbonate => calcium oxide + carbon dioxide
4. glucose => ethanol + carbon dioxide
Which of the following is a 'endothermic' reaction? [rt-8]
1. methane + oxygen => carbon dioxide + water
2. sodium hydroxide + hydrochloric acid => sodium chloride + water
3. calcium oxide + carbon dioxide ==> calcium carbonate
4. ammonia ==> nitrogen + hydrogen
Which is a 'neutralisation' reaction to form a soluble salt? [rt-9]
1. CuO_(s) + H₂SO_4(aq) ==> CuSO_4(aq) + H₂O_(l)
2. 2Al_(s) + Fe₂O_3(s) ==> 2Fe_(s) + Al₂O_3(s)
3. C₆H_14(g) ==> C₂H_4(g) + C₄H_10(g)
4. 2NH_3(g) ==> N_2(g) + 3H_2(g)
Which is a 'neutralisation' reaction to form a soluble salt? [rt-13]
1. copper oxide + sulfuric acid => copper sulfate + water
2. aluminium + iron oxide => aluminium oxide + iron
3. hexane => ethene + butane
4. calcium hydroxide + carbon dioxide => calcium carbonate + water
Which of the following is a 'displacement' reaction? [rt-17]
1. Mg_(s) + CuSO_4(aq) ==> Cu_(s) + MgSO_4(aq)
2. C₆H_14(g) => C₂H_4(g) + C₄H_10(g)
3. C₆H₁₂O_6(aq) + 6O_2(g) ==> 6CO_2(g) + 6H₂O_(l)
4. 2NH_3(g) ==> N_2(g) + 3H_2(g)
Which of the following is a 'thermal decomposition'? [rt-18]
1. Mg_(s) + CuSO_4(aq) ==> Cu_(s) + MgSO_4(aq)
2. C₆H_14(g) => C₂H_4(g) + C₄H_10(g)
3. C₆H₁₂O_6(aq) + 6O_2(g) ==> 6CO_2(g) + 6H₂O_(l)
4. Na₂SO_4(aq) + BaCl_2(aq) ==> 2NaCl_(aq) + BaSO_4(aq)
Which of the following represents 'respiration'? [rt-19]
1. Mg_(s) + CuSO_4(aq) ==> Cu_(s) + MgSO_4(aq)
2. C₆H_14(g) => C₂H_4(g) + C₄H_10(g)
3. C₆H₁₂O_6(aq) + 6O_2(g) ==> 6CO_2(g) + 6H₂O_(l)
4. 2NH_3(g) ==> N_2(g) + 3H_2(g)
Which of the following is a 'displacement' reaction? [rt-21]
1. magnesium + copper sulfate ==> copper + magnesium sulfate
2. hexane ==> ethene + butane
3. glucose + oxygen ==> carbon dioxide + water
4. ammonia ==> nitrogen + ammonia
Which of the following is a 'thermal decomposition'? [rt-22]
1. magnesium + copper sulfate ==> copper + magnesium sulfate
2. hexane ==> ethene + butane
3. glucose + oxygen ==> carbon dioxide + water
4. nitrogen + hydrogen ==> ammonia
Which of the following represents 'respiration'? [rt-23]
1. magnesium + copper sulfate ==> copper + magnesium sulfate
2. hexane ==> ethene + butane
3. glucose + oxygen ==> carbon dioxide + water
4. 2NH_3(g) ==> N_2(g) + 3H_2(g)
Which of A to D represents 'photosynthesis'? [rt-25]
1. 6CO_2(g) + 6H₂O_(l) ==> C₆H₁₂O_6(aq) + 6O_2(g)
2. n CH₂=CH₂ ==> (-CH₂-CH₂-)_n
3. N_2(g) + 3H_2(g) ==> 2NH_3(g)
4. CH_4(g) + 2O_2(g) ==> CO_2(g) + 2H₂O_(l)
Which of A to D represents a 'polymerisation' reaction? [rt-26]
1. 6CO_2(g) + 6H₂O_(l) ==> C₆H₁₂O_6(aq) + 6O_2(g)
2. n CH₂=CH₂ ==> (-CH₂-CH₂-)_n
3. N_2(g) + 3H_2(g) ==> 2NH_3(g)
4. CH_4(g) + 2O_2(g) ==> CO_2(g) + 2H₂O_(l)
Which of A to D represents a 'burning' reaction? [rt-28]
1. 6CO_2(g) + 6H₂O_(l) ==> C₆H₁₂O_6(aq) + 6O_2(g)
2. n CH₂=CH₂ ==> (-CH₂-CH₂-)_n
3. N_2(g) + 3H_2(g) ==> 2NH_3(g)
4. CH_4(g) + 2O_2(g) ==> CO_2(g) + 2H₂O_(l)
Which of A to D represents 'photosynthesis'? [rt-29]
1. carbon dioxide + water ==> glucose + oxygen
2. ethene ==> poly(ethene)
3. nitrogen + hydrogen ==> ammonia
4. methane + oxygen ==> carbon dioxide + water
Which of A to D represents a 'plastic forming' reaction? [rt-30]
1. carbon dioxide + water ==> glucose + oxygen
2. ethene ==> poly(ethene)
3. nitrogen + hydrogen ==> ammonia
4. methane + oxygen ==> carbon dioxide + water
Which of A to D represents a 'burning' reaction? [rt-32]
1. carbon dioxide + water ==> glucose + oxygen
2. ethene ==> poly(ethene)
3. nitrogen + hydrogen ==> ammonia
4. methane + oxygen ==> carbon dioxide + water
Which description means an 'EXOTHERMIC REACTION'? [rt-33]
1. heat energy is given out by the reaction
2. heat energy is taken in by the reaction
3. the temperature falls as the reaction proceeds
4. the mass of the chemicals increases
Which description means an 'ENDOTHERMIC REACTION'? [rt-34]
1. heat energy is given out by the reaction
2. heat energy is taken in by the reaction
3. the temperature rises as the reaction proceeds
4. the mass of the chemicals decreases
Which of the following is an ENDOTHERMIC chemical change? [rt-37]
1. calcium carbonate => calcium oxide + carbon dioxide
2. methane + oxygen => carbon dioxide + water
3. sodium hydroxide + hydrochloric acid => sodium chloride + water
4. glucose + oxygen => water + carbon dioxide
Which of the following is an ENDOTHERMIC chemical change? [rt-38]
1. methane + oxygen => carbon dioxide + water
2. hexane => ethane + propene
3. sodium hydroxide + hydrochloric acid => sodium chloride + water
4. glucose + oxygen => water + carbon dioxide
Which of the following is an ENDOTHERMIC chemical change? [rt-39]
1. sodium hydroxide + hydrochloric acid => sodium chloride + water
2. methane + oxygen => carbon dioxide + water
3. water + carbon dioxide => glucose + oxygen
4. glucose + oxygen => water + carbon dioxide
Which of the following is an ENDOTHERMIC chemical change? [rt-40]
1. sodium hydroxide + hydrochloric acid => sodium chloride + water
2. methane + oxygen => carbon dioxide + water
3. glucose + oxygen => water + carbon dioxide
4. sodium chloride => sodium + chlorine
Which of the following is an EXOTHERMIC chemical change? [rt-41]
1. sodium hydroxide + hydrochloric acid ==> sodium chloride + water
2. calcium carbonate ==> calcium oxide + carbon dioxide
3. hexane ==> ethane + propene
4. water + carbon dioxide ==> glucose + oxygen
Which of the following is an EXOTHERMIC chemical change? [rt-42]
1. calcium carbonate ==> calcium oxide + carbon dioxide
2. methane + oxygen ==> carbon dioxide + water
3. hexane ==> ethane + propene
4. water + carbon dioxide ==> glucose + oxygen
Which of the following is an EXOTHERMIC chemical change? [rt-43]
1. calcium carbonate ==> calcium oxide + carbon dioxide
2. hexane ==> ethane + propene
3. glucose + oxygen ==> water + carbon dioxide
4. sodium chloride ==> sodium + chlorine
Which of the following is an EXOTHERMIC chemical change? [rt-44]
1. calcium carbonate => calcium oxide + carbon dioxide
2. hexane => ethane + propene
3. water + carbon dioxide => glucose + oxygen
4. sodium + chlorine => sodium chloride
For the following reaction: Fe₂O₃ + 3CO ==> 2Fe + 3CO₂
Which is 'reduced? [rt-57]
1. Fe₂O₃
2. CO
3. Fe
4. CO₂
For the following reaction: Fe₂O₃ + 3CO ==> 2Fe + 3CO₂
Which is 'oxidised? [rt-58]
1. Fe₂O₃
2. CO
3. Fe
4. CO₂
Which of the following corresponds to the 'limekiln reaction'? [rt-63]
1. N_{2 (g)} + 3H_{2 (g)} ==> 2NH_{3 (g)}
2. 2SO_{2 (g)} + O_{2 (g)} ==> 2SO_{3 (g)}
3. CaCO_{3 (s)} => CaO_(s) + CO_{2 (g)}
4. 2CO_(g) + 2NO_(g) ==> 2CO_{2 (g)} + N_{2 (g)}
For the reaction: copper oxide + hydrogen ==> copper + water
... which of the following is 'reduced'? [rt-65]
1. copper oxide
2. hydrogen
3. copper
4. water
For the reaction: copper oxide + hydrogen ==> copper + water
... which of the following is 'oxidised'? [rt-66]
1. copper oxide
2. hydrogen
3. copper
4. water
[7f-113] The picture equation shows a chemical reaction between copper carbonate and sulfuric acid, Which is an incorrectly written formula?
1. CuO₃C
2. H₂SO₄
3. CuSO₄
4. CO₂
5. H₂O
[7f-114] The picture equation shows a chemical reaction between copper carbonate and sulfuric acid, Which is an incorrectly written formula?
1. CuCO₃
2. H₂O₄S
3. CuSO₄
4. CO₂
5. H₂O
[7f-115] The picture equation shows a chemical reaction between copper carbonate and sulfuric acid, Which is an incorrectly written formula?
1. CuCO₃
2. H₂SO₄
3. CuO₄S
4. CO₂
5. H₂O
[7f-116] The picture equation shows a chemical reaction between copper carbonate and sulfuric acid, Which is an incorrectly written formula?
1. CuCO₃
2. H₂SO₄
3. CuSO₄
4. C₂O
5. H₂O
[7f-117] The picture equation shows a chemical reaction between copper carbonate and sulfuric acid, Which is an incorrectly written formula?
1. CuCO₃
2. H₂SO₄
3. CuSO₄
4. CO₂
5. HO₂
Which of the following is NOT true about catalysts? [7f-118]
1. they slow down reactions to make them safer
2. they lower the activation energy needed for a reaction to happen
3. they are not consumed in the chemical process and can be reused
4. they enable a lower temperature to be used to carry out a chemical reaction, so saving energy
5. a catalyst remains chemically unchanged at the end of a reaction
6. they can be expensive and cleaned or replaced due to 'poisoning' by impurities in the reactants
Which of the following is NOT true about catalysts? [7f-118]
1. they speed up reactions
2. they raise the activation energy needed for a reaction to happen
3. they are not consumed in the chemical process and can be reused
4. they enable a lower temperature to be used to carry out a chemical reaction, so saving energy
5. a catalyst remains chemically unchanged at the end of a reaction
6. they can be expensive and cleaned or replaced due to 'poisoning' by impurities in the reactants
Which of the following is NOT true about catalysts? [7f-119]
1. they speed up reactions
2. they lower the activation energy needed for a reaction to happen
3. they are unfortunately consumed in the chemical process and can't be reused
4. they enable a lower temperature to be used to carry out a chemical reaction, so saving energy
5. a catalyst remains chemically unchanged at the end of a reaction
6. they can be expensive and cleaned or replaced due to 'poisoning' by impurities in the reactants
Which of the following is NOT true about catalysts? [7f-120]
1. they speed up reactions
2. they lower the activation energy needed for a reaction to happen
3. they are not consumed in the chemical process and can be reused
4. they enable a higher temperature to be used to carry out a chemical reaction, so saving energy
5. a catalyst remains chemically unchanged at the end of a reaction
6. they can be expensive and cleaned or replaced due to 'poisoning' by impurities in the reactants
Which of the following is NOT true about catalysts? [7f-121]
1. they speed up reactions
2. they lower the activation energy needed for a reaction to happen
3. they are not consumed in the chemical process and can be reused
4. they enable a lower temperature to be used to carry out a chemical reaction, so saving energy
5. a catalyst is chemically changed at the end of a reaction
6. they can be expensive and cleaned or replaced due to 'poisoning' by impurities in the reactants
Which of the following is NOT true about catalysts? [7f-122]
1. they speed up reactions
2. they lower the activation energy needed for a reaction to happen
3. they are not consumed in the chemical process and can be reused
4. they enable a lower temperature to be used to carry out a chemical reaction, so saving energy
5. a catalyst remains chemically unchanged at the end of a reaction
6. they are usually quite cheap to make and use
Which of the following is a 'displacement reaction'? [7f-123]
1. CH_4(g) + 2O_2(g) ==> CO_2(g) + 2H₂O_(l)
2. NaOH_(aq) + HCl_(aq) ==> NaCl_(aq) + H₂O_(l)
3. CaCO_3(s) ==> CaO_(s) + CO_2(g)
4. C₆H₁₂O_6(aq) ==> 2C₂H₅OH_(aq) + 2CO_2(g)
Which phrase specifically means "a reaction of a substance with oxygen to make new substances in which energy is transferred to the surroundings as thermal heat energy and light"? [7f-124]
1. combustion reaction
2. thermal decomposition reaction
3. displacement reaction
4. endothermic
5. exothermic
6. oxidation
7. reduction
Which phrase specifically means "a reaction where a single reactant is broken down into two or more simpler products by strongly heating"? [7f-125]
1. combustion reaction
2. thermal decomposition reaction
3. displacement reaction
4. endothermic
5. exothermic
6. oxidation
7. reduction
Which phrase specifically means "a reaction where something replaces something else in a formula"? [7f-126]
1. combustion reaction
2. thermal decomposition reaction
3. displacement reaction
4. endothermic
5. exothermic
6. oxidation
7. reduction
Which phrase specifically means "a reaction is where energy is taken in, usually as thermal heat energy, but can be light or electricity"? [7f-127]
1. combustion reaction
2. thermal decomposition reaction
3. displacement reaction
4. endothermic
5. exothermic
6. oxidation
7. reduction
Which phrase specifically means "a reaction is where energy is given out, usually as heat, but can be light or electricity"? [7f-128]
1. combustion reaction
2. thermal decomposition reaction
3. displacement reaction
4. endothermic
5. exothermic
6. oxidation
7. reduction
Which phrase specifically means "a reaction in which a substance combines with oxygen (gains oxygen)"? [7f-129]
1. combustion reaction
2. thermal decomposition reaction
3. displacement reaction
4. endothermic
5. exothermic
6. oxidation
7. reduction
Which phrase specifically means "a reaction in which a substance loses oxygen"? [7f-130]
1. combustion reaction
2. thermal decomposition reaction
3. displacement reaction
4. endothermic
5. exothermic
6. oxidation
7. reduction
6.4 g of fragments pure copper metal was heated in a crucible until it all turned black and the contents of the crucible then weighed 8.0 g?
Which of the following is NOT true [7f-131]
1. the copper combined with 1.6 g of nitrogen from air
2. the colour change was a strong indication that a chemical reaction had taken place
3. the word equation is: copper + oxygen ==> copper oxide
4. the balanced symbol equation is: 2Cu + O₂ ==> 2CuO
5. the black substance was copper oxide
6.4 g of fragments pure copper metal was heated in a crucible until it all turned black and the contents of the crucible then weighed 8.0 g?
Which of the following is NOT true [7f-132]
1. the copper combined with 1.6 g of oxygen from air
2. the colour change was a strong indication that a physical change had taken place
3. the word equation is: copper + oxygen ==> copper oxide
4. the balanced symbol equation is: 2Cu + O₂ ==> 2CuO
5. the black substance was copper oxide
6.4 g of fragments pure copper metal was heated in a crucible until it all turned black and the contents of the crucible then weighed 8.0 g?
Which of the following is NOT true [7f-133]
1. the copper combined with 1.6 g of oxygen from air
2. the colour change was a strong indication that a chemical reaction had taken place
3. the word equation is: copper + nitrogen ==> copper nitride
4. the balanced symbol equation is: 2Cu + O₂ ==> 2CuO
5. the black substance was copper oxide
6.4 g of fragments pure copper metal was heated in a crucible until it all turned black and the contents of the crucible then weighed 8.0 g?
Which of the following is NOT true [7f-134]
1. the copper combined with 1.6 g of oxygen from air
2. the colour change was a strong indication that a chemical reaction had taken place
3. the word equation is: copper + oxygen ==> copper oxide
4. the balanced symbol equation is: Cu + O₂ ==> Cu₂O
5. the black substance was copper oxide
6.4 g of fragments pure copper metal was heated in a crucible until it all turned black and the contents of the crucible then weighed 8.0 g?
Which of the following is NOT true [7f-135]
1. the copper combined with 1.6 g of oxygen from air
2. the colour change was a strong indication that a chemical reaction had taken place
3. the word equation is: copper + oxygen ==> copper oxide
4. the balanced symbol equation is: 2Cu + O₂ ==> 2CuO
5. the black substance was copper nitride
3.6 g of magnesium ribbon was strongly heated in a crucible until it all turned white and the contents of the crucible then weighed 6.0 g?
Which of the following is NOT true [7f-136]
1. the magnesium combined with 3.6 g of oxygen from air
2. the colour change was a strong indication that a chemical reaction had taken place
3. the word equation is: magnesium + oxygen ==> magnesium oxide
4. the balanced symbol equation is: 2Mg + O₂ ==> 2MgO
5. the white substance was magnesium oxide
3.6 g of magnesium ribbon was strongly heated in a crucible until it all turned white and the contents of the crucible then weighed 6.0 g?
Which of the following is NOT true [7f-137]
1. the magnesium combined with 2.4 g of oxygen from air
2. the colour change was a strong indication that a physical change had taken place
3. the word equation is: magnesium + oxygen ==> magnesium oxide
4. the balanced symbol equation is: 2Mg + O₂ ==> 2MgO
5. the white substance was magnesium oxide
3.6 g of magnesium ribbon was strongly heated in a crucible until it all turned white and the contents of the crucible then weighed 6.0 g?
Which of the following is NOT true [7f-138]
1. the magnesium combined with 2.4 g of oxygen from air
2. the colour change was a strong indication that a chemical reaction had taken place
3. the word equation is: magnesium + nitrogen ==> magnesium nitride
4. the balanced symbol equation is: 2Mg + O₂ ==> 2MgO
5. the white substance was magnesium oxide
3.6 g of magnesium ribbon was strongly heated in a crucible until it all turned white and the contents of the crucible then weighed 6.0 g?
Which of the following is NOT true [7f-139]
1. the magnesium combined with 2.4 g of oxygen from air
2. the colour change was a strong indication that a chemical reaction had taken place
3. the word equation is: magnesium + oxygen ==> magnesium oxide
4. the balanced symbol equation is: Mg + O₂ ==> Mg₂O
5. the white substance was magnesium oxide
3.6 g of magnesium ribbon was strongly heated in a crucible until it all turned white and the contents of the crucible then weighed 6.0 g?
Which of the following is NOT true [7f-140]
1. the magnesium combined with 2.4 g of oxygen from air
2. the colour change was a strong indication that a chemical reaction had taken place
3. the word equation is: magnesium + oxygen ==> magnesium oxide
4. the balanced symbol equation is: 2Mg + O₂ ==> 2MgO
5. the white substance was magnesium nitride
[7f-141] Ammonia, used in synthetic fertilisers, is made by passing nitrogen and hydrogen over finely divided iron in a reaction that gives out heat energy. Given the following symbol equation:
N₂ + 3H₂ == Fe ==> 2NH₃
Which pair of words apply to this reaction?
1. activated, endothermic
2. activated, exothermic
3. catalysed, endothermic
4. catalysed, exothermic
[7f-142] In a catalytic converter in a car exhaust, the gases are passed over finely divided platinum to oxidise carbon monoxide to carbon dioxide. Given the following symbol equation:
2CO + O₂ == Pt ==> 2CO₂
Which pair of words apply to this reaction?
1. activated, endothermic
2. activated, exothermic
3. catalysed, endothermic
4. catalysed, exothermic
[7f-143] The particle model equation diagram shows the combustion of methane.
Which of the following statements is NOT true?
1. a physical change is where a substance changes state, and the substance changes into a new substance
2. a reaction is exothermic because more energy is released when new bonds are formed in the products than the energy needed to break the original bonds in the reactants
3. in a chemical reaction, atoms rearrange the way they are joined together and a new substance is formed
4. chemical changes are not usually easily reversed but physical state changes are
5. compounds formed from reactions between elements have completely different properties from the original elements
6. compounds are not mixtures, and are formed by a chemical combination of two or more different elements, not easily separated
[7f-144] The particle model equation diagram shows the combustion of methane.
Which of the following statements is NOT true?
1. a physical change is where a substance changes state, but the substance does not change chemically, so no new substance is formed
2. a reaction is endothermic because more energy is released when new bonds are formed in the products than the energy needed to break the original bonds in the reactants
3. in a chemical reaction, atoms rearrange the way they are joined together and a new substance is formed
4. chemical changes are not usually easily reversed but physical state changes are
5. compounds formed from reactions between elements have completely different properties from the original elements
6. compounds are not mixtures, and are formed by a chemical combination of two or more different elements, not easily separated
[7f-145] The particle model equation diagram shows the combustion of methane.
Which of the following statements is NOT true?
1. a physical change is where a substance changes state, but the substance does not change chemically, so no new substance is formed
2. a reaction is exothermic because more energy is released when new bonds are formed in the products than the energy needed to break the original bonds in the reactants
3. in a physical change, atoms rearrange the way they are joined together and a new substance is formed
4. chemical changes are not usually easily reversed but physical state changes are
5. compounds formed from reactions between elements have completely different properties from the original elements
6. compounds are not mixtures, and are formed by a chemical combination of two or more different elements, not easily separated
[7f-146] The particle model equation diagram shows the combustion of methane.
Which of the following statements is NOT true?
1. a physical change is where a substance changes state, but the substance does not change chemically, so no new substance is formed
2. a reaction is exothermic because more energy is released when new bonds are formed in the products than the energy needed to break the original bonds in the reactants
3. in a chemical reaction, atoms rearrange the way they are joined together and a new substance is formed
4. chemical changes are usually easily reversed like physical changes of state
5. compounds formed from reactions between elements have completely different properties from the original elements
6. compounds are not mixtures, and are formed by a chemical combination of two or more different elements, not easily separated
[7f-147] The particle model equation diagram shows the combustion of methane.
Which of the following statements is NOT true?
1. a physical change is where a substance changes state, but the substance does not change chemically, so no new substance is formed
2. a reaction is exothermic because more energy is released when new bonds are formed in the products than the energy needed to break the original bonds in the reactants
3. in a chemical reaction, atoms rearrange the way they are joined together and a new substance is formed
4. chemical changes are not usually easily reversed but physical state changes are
5. compounds formed from reactions between elements have the average properties of the original elements
6. compounds are not mixtures, and are formed by a chemical combination of two or more different elements, not easily separated
[7f-148] The particle model equation diagram shows the combustion of methane.
Which of the following statements is NOT true?
1. a physical change is where a substance changes state, but the substance does not change chemically, so no new substance is formed
2. a reaction is exothermic because more energy is released when new bonds are formed in the products than the energy needed to break the original bonds in the reactants
3. in a chemical reaction, atoms rearrange the way they are joined together and a new substance is formed
4. chemical changes are not usually easily reversed but physical state changes are
5. compounds formed from reactions between elements have completely different properties from the original elements
6. compounds are mixtures formed by a chemical combination of two or more different elements
It is important to recognise the different parts of a formula to understand how it might be named.
[7f-149] The chemical name for the OH part of a formula is?
1. hydroxide
2. oxide
3. oxyhydride
4. hydroxyide
It is important to recognise the different parts of a formula to understand how it might be named.
[7f-150] The chemical name for the CO₃ part of a formula is?
1. carbide
2. carbonate
3. hydrogencarbonate
4. carbonite
It is important to recognise the different parts of a formula to understand how it might be named.
[7f-151] The chemical name for the SO₄ part of a formula is?
1. sulfide
2. sulfite
3. sulfate
4. oxysulfate
It is important to recognise the different parts of a formula to understand how it might be named.
[7f-152] The chemical name for the NO₃ part of a formula is?
1. nitrite
2. nitride
3. oxynitrate
4. nitrate
[7f-153] Which of the particle diagrams for chemical reactions represents the formation of water from its elements?
[7f-154] Which of the particle diagrams for chemical reactions represents the formation of a compound from two elements?
[7f-155] Which of the particle diagrams for chemical reactions represents the thermal decomposition of calcium carbonate (limestone)?
[7f-156] Which of the particle diagrams for chemical reactions represents the decomposition of a compound into two compounds?
[7f-157] Which of the particle diagrams for chemical reactions represents the oxidation of carbon monoxide to give carbon dioxide?
[7f-158] Which of the particle diagrams for chemical reactions represents a reaction between an element and a compound to give a single compound?
[7f-159] Which of the particle diagrams for chemical reactions represents the reduction of a metal oxide to yield the free metal?
[7f-160] Which of the particle diagrams for chemical reactions represents the reduction of copper oxide with hydrogen to yield free copper atoms?
[7f-161] Which of the particle diagrams for chemical reactions represents a reaction between an element and a compound giving another element and compound products?
[7f-162] Which of the particle diagrams for chemical reactions represents a reaction between a metal and an acid?
[7f-163] Which of the particle diagrams for chemical reactions represents an metallic element + acidic compound ==> compound + gaseous element reaction?
[7f-164] Which of the particle diagrams for chemical reactions represents an a metal-metal displacement reaction?
[7f-165] Which of the particle diagrams for chemical reactions represents an element + compound ==> compound + element reaction involving metals and sulfate salts?
[7f-166] Which of the particle diagrams for chemical reactions represents an oxidation reaction between a metal and oxygen forming a metal oxide?
[7f-167] Which of the particle diagrams for chemical reactions represents an element + element ==> compound reaction?