Chap 19 Rate of Reactions

A liquid X reacts with solid Y to form a gas.

Which two diagrams show suitable methods for investigating the rate (speed) of the reaction?

• A

• B

• C

• D

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The results of two separate reactions between excess calcium carbonate and hydrochloric acid

are shown.

Which statement explains the differences between the reactions?

• More calcium carbonate was used in the second reaction.

• The same volume of more concentrated acid was used in the second reaction.

• The second reaction was allowed to react for longer.

• The temperature was higher in the second reaction.

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Magnesium is reacted with a dilute acid.

The hydrogen gas is collected and its volume measured.

The results are shown on the graph.

Between which times was the reaction fastest?

• 0 and 1 minute

• 1 and 2 minutes

• 2 and 3 minutes

• 7 and 8 minutes

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The effect of temperature on the rate of the reaction between marble chips and hydrochloric acid

can be investigated by measuring the production of carbon dioxide.

Which item of equipment is not required for the investigation?

• condenser

• gas syringe

• stopclock

• thermometer

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The diagram shows four experiments in which equal volumes of aqueous acid (all in an excess)

are added to equal masses of metal. Both acids have the same concentration.

In which experiment has the metal completely reacted in the shortest time?

• A

• B

• C

• D

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The diagram shows apparatus being used to demonstrate how the rate of a chemical reaction

changes with temperature.

Which statement must be correct?

• The reaction is endothermic.

• The reaction is exothermic.

• The reaction produces a gas.

• The reaction produces an acid.

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Which of the following changes decreases the rate of the reaction between magnesium and dilute

hydrochloric acid?

1 diluting the acid

2 using larger pieces of magnesium

3 cooling the mixture

• 1 and 3 only

• 1, 2, 3

• 1 and 2 only

• 2 and 3 only

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Powdered marble reacts with hydrochloric acid using the apparatus shown. The gas syringe fills in 36 seconds.

The experiment is repeated using marble chips in place of powdered marble.

How long does it take to fill the gas syringe in this experiment?

• 9 seconds

• 18 seconds

• 36 seconds

• 72 seconds

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A simple way of making bread includes

1 Mixing flour with a small amount of yeast and some water to make a ‘dough’.

2 Leaving the dough in a warm place for the yeast to act on the dough to form carbon

dioxide which increases the volume of the dough.

Which factors affecting a reaction rate are involved in bread making?

• A

• B

• C

• D

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The diagram shows an experiment to measure the rate of a chemical reaction.

Which change decreases the rate of reaction?

• adding water to the flask

• heating the flask during the reaction

• using more concentrated acid

• using powdered metal

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