Rates of reaction and energy changes test questions - National 4 Chemistry Revision

1

Which of these factors will speed up a chemical reaction?

Decreasing the temperature of the reaction

Decreasing the particle size of reactants

Decreasing the concentration of reactants

2

In an experiment calcium carbonate was added to hydrochloric acid and the volume of gas given off was measured.

This graph was drawn from the results.

Graph of total volume of product against time from start of reaction.

The pink line shows Experiment A. The green line shows Experiment B.

Which of the following statements is correct?

Experiment A was 5g of calcium carbonate chips, B was 5g of calcium carbonate powder

Experiment A was 2.5g of calcium carbonate chips, B was 5g of calcium carbonate chips

Experiment A was 5g of calcium carbonate powder, B was 5g of calcium carbonate chips

3

Cutting potatoes into smaller pieces makes them cook faster when they are boiled.

Which of the following correctly explains why this happens?

The smaller potatoes have a larger surface area

The smaller potatoes cook at a higher temperature

The knife acts as a catalyst in the reaction

4

Which of the following could not be used to directly measure the volume of a gas given off during a reaction?

A gas syringe

A balance

A trough of water and a measuring cylinder

5

When a fuel burns it reacts with oxygen and gives out heat and light energy.

How can this reaction be described?

Exothermic

Endothermic

Neutralisation

6

Which of the following reactions would be the slowest?

0.5 mol/l hydrochloric acid reacting with zinc powder

1mol/l hydrochloric acid with zinc powder

0.5 mol/l hydrochloric acid reacting with a lump of zinc

7

In which of the following reactions would hydrogen be produced the fastest?

Calcium powder and 2 mol/l hydrochloric acid

Calcium lumps and 2 mol/l hydrochloric acid

Calcium powder and 4 mol/l hydrochloric acid

8

What does a catalyst do?

Speeds up a reaction and is not used up in the reaction

Slows down a reaction and is not used up in the reaction

Speeds up a reaction and is used up in the reaction

9

Which factor is always measured when comparing the rate of reactions?

Temperature

Change in volume

Time

10

Which line on this rate graph shows the slowest reaction?

Graph of mass of product produced against time from start of reaction, with 3 lines plotted. They all start at zero and level off at the same mass of product produced. Line A has the highest gradient. Line C has the lowest. The gradient of line B is between those of A and C.