Quiz on Reaction Kinetics, Enthalpy and Electrochemistry SK025

What is the unit of reaction rate?

• mol L⁻¹ s⁻¹

• mol L⁻¹ min⁻¹

• mol L⁻¹ h⁻¹

• mol L⁻¹ day⁻¹

Which of the following is true about the differential rate equation?

• It relates the rate of disappearance of reactants to the rate of appearance of products.

• It only applies to reactions with solid reactants.

• It is used to determine the equilibrium constant.

• It is independent of the stoichiometric coefficients.

For the reaction 2HI(g) → H₂(g) + I₂(g), if the rate of formation of I₂ is 1.8 x 10⁻⁶ M s⁻¹, what is the rate of disappearance of HI?

• 1.8 x 10⁻⁶ M s⁻¹

• 3.6 x 10⁻⁶ M s⁻¹

• 0.9 x 10⁻⁶ M s⁻¹

• 2.7 x 10⁻⁶ M s⁻¹

What is the overall order of reaction for the rate law: rate = k [NO]² [O₂]?

• 1

• 2

• 3

• 4

Which of the following is NOT a requirement for an effective collision according to collision theory?

• Molecules must collide.

• Colliding molecules must possess a minimum kinetic energy.

• Molecules must collide in the correct orientation.

• Molecules must be in the gaseous state.

What is activation energy (Ea)?

• The energy required to break bonds in reactants.

• The minimum energy required to initiate a chemical reaction.

• The energy released during a chemical reaction.

• The energy required to form products.

For the reaction A + B → C + D, if the activation energy of the forward reaction is 84 kJ mol⁻¹ and the enthalpy change is +21 kJ mol⁻¹, what is the activation energy of the reverse reaction?

• 63 kJ mol⁻¹

• 105 kJ mol⁻¹

• 84 kJ mol⁻¹

• 21 kJ mol⁻¹

Which factor increases the reaction rate by providing an alternative pathway with a lower activation energy?

• Concentration

• Temperature

• Catalyst

• Particle size

Which of the following statements is true about the effect of particle size on reaction rate?

• Larger particles increase the reaction rate.

• Smaller particles decrease the reaction rate.

• Smaller particles increase the reaction rate.

• Particle size has no effect on the reaction rate.

What is the standard condition for measuring enthalpies?

• 0°C and 1 atm

• 25°C and 1 atm

• 50°C and 2 atm

• 100°C and 1 atm