Chemistry Practice Test – Rate of Chemical Reactions (Questions with Answers and Explanations)

Na₂S₂O_4(aq) + 2HCl_(aq) —> 2NaCl_(aq) + H₂O_(l) + SO_2(g) + S_(s)

Which of the following would introduce the greatest increase in the rate of the chemical reaction above? (JAMB 2007)

A. A decrease in temperature and an increase in the concentration of the reactants.
B. An increase in temperature and a decrease in the concentration of the reactants.
C. An increase in temperature and an increase in the concentration of the reactants.
D. A decrease in volume and an increase in the pressure of the reactants.

A catalyst speeds up the rate of a chemical reaction by ______ (JAMB 2021)

A. taking part in the reaction
B. polymerizing
C. increasing the activation energy
D. lowering the activation energy

To increase the rate of chemical reaction, a catalyst ______ (JAMB 2019)

A. decreases the activation energy
B. increases the activation energy
C. decreases the collision frequency
D. increases the collision frequency

The decomposition of hydrogen peroxide is faster in the presence of _______ (JAMB 2018)

A. manganese (IV) oxide
B. vanadium (V) oxide
C. iron
D. nickel

Mineral acids are usually added to commercial hydrogen peroxide to ________ (JAMB 2012)

A. oxidize it
B. decompose it
C. minimize its decomposition
D. reduce it to water and oxygen.