CAIE IGCSE Chemistry 6.2 Rate of Reaction Topic Practice

Powdered magnesium carbonate is added to excess dilute hydrochloric acid.
The total volume of gas produced is measured over time.
A graph of the results is shown.

The experiment is repeated but the concentration of the hydrochloric acid is doubled.

All other conditions are kept the same.
Which statements about the second experiment are correct?

1 The final volume of gas is $360 \mathrm{~cm}^{3}$.
2 The reaction finishes before 90 seconds.
3 The activation energy of the reaction is lower.

The equation for the decomposition of hydrogen peroxide, $\mathrm{H}_{2} \mathrm{O}_{2}$, is shown.

In an experiment, the total volume of oxygen produced is $100 \mathrm{~cm}^{3}$.
The experiment is repeated using 1.00 g of a solid catalyst. All other conditions remain the same.
Which row describes the total volume of oxygen and the mass of the catalyst at the end of the second experiment?

The apparatus shown is used to measure the rate of a reaction.

Which equation represents a reaction where the rate can be measured using this apparatus?

A student adds excess magnesium ribbon to $10 \mathrm{~cm}^{3}$ of $0.5 \mathrm{~mol} / \mathrm{dm}^{3}$ sulfuric acid.
The hydrogen gas produced is collected and its total volume is measured every 10 seconds.
The experiment is repeated with $5 \mathrm{~cm}^{3}$ of $0.5 \mathrm{~mol} / \mathrm{dm}^{3}$ sulfuric acid added to $5 \mathrm{~cm}^{3}$ of water using the same mass of magnesium ribbon.

Which line on the graph shows the results of the second experiment?

Which change in conditions increases the energy of the particles in a reaction?

Which statements explain why increasing the temperature changes the rate of a chemical reaction?

1 It increases the activation energy.
2 It increases the frequency of collisions between the reacting particles.
3 It increases the kinetic energy of the reacting particles.
4 It increases the number of particles per unit volume.

Hydrogen iodide thermally decomposes into iodine and hydrogen. The reaction is reversible.

Fig. 4.1 shows a gas syringe containing a mixture of hydrogen iodide, iodine and hydrogen gases. The gas syringe is sealed and the mixture is heated to $300^{\circ} \mathrm{C}$. The mixture of gases reaches equilibrium and is purple.

Methanol is manufactured by reacting carbon monoxide with hydrogen.

The rate of formation of methanol increases when a catalyst is used.

State the effect that a catalyst has on the activation energy, $E_{\mathrm{a}}$, of a reaction.