Stogs GCSE Interleaving Rates S

How can rate of reaction be measured in reactions?

• Measure mass lost when gas produced.

• Measure volume of gas produced.

• Measure colour change or formation of a solid.

• Measure time taken for liquid to disappear.

Look at the graph. At what time does the reaction finish?

• 4 minutes

• 5 minutes

• 6 minutes

• 7 minutes

Look at the graph. Use the tangent to the curve to work out the rate of reaction.

• 0.5

• 1

• 1.5

• 2

Look at the graph. What does the tangent to the curve show?

• Time taken

• Concentration

• Rate

• Mass

The same mass of smaller marble chips would...

• React faster as they have a smaller surface area to volume ratio.

• React more slowly as they have a smaller surface area to volume ratio.

• React faster as they have a larger surface area to volume ratio.

• React more slowly as they have a larger surface area to volume ratio.

A student investigates the rate of reaction between zinc and excess dilute hydrochloric acid.

The table shows his results. What is the rate of the reaction?

• 8.2

• 8.4

• 21

• 84

The decomposition of hydrogen peroxide is catalysed by adding a small amount of manganese (IV) oxide. Which of the graphs below shows the mass of the catalyst as the reaction takes place?

• A

• B

• C

• D

Zinc reacts with dilute hydrochloric acid to produce zinc chloride and hydrogen.

When zinc powder is used, instead of larger pieces of zinc, the reaction is faster. Why is this?

• The activation energy is lower so a greater proportion of reactions are successful.

• The particles have more energy so move around faster and collide more frequently.

• Greater surface area means particles collide more frequently.

• More particles are in a given volume so the activation energy decreases.

Catalytic converters in the exhaust systems of cars contain catalysts.

Explain what is meant by the term catalyst.

• A species which decreases the activation energy as it reacts.

• A species which increases the rate of a reaction without being chemically changed itself.

• A species which reacts to make a product which changes the colour of a reaction.

• Something that is added and has no effect on the reaction.

A student carries out an experiment to measure accurately the temperature changes when different metals are added to iron(II) sulfate solution. State a suitable container to measure the iron(II) sulfate solution in this experiment.

• Beaker

• Measuring cylinder

• Spatula

• Mass balance