Expert Chemistry Tutoring

Q1 - Knowledge Recall (2 marks)

Define collision theory and state one factor that affects the rate of a reaction according to it.

Q2 - Application (2 marks)

Explain how increasing the temperature of a reaction can increase the rate of reaction according to collision theory.

Q3 - Calculation (3 marks)

If the rate constant for a reaction is 2.5 x 10^-3 mol dm^-3 s^-1, and the initial concentration of the reactants is 0.5 mol dm^-3, calculate the initial rate of reaction.

Q4 - Knowledge Recall (1 mark)

State what is meant by the activation energy of a reaction.

Q5 - Application (2 marks)

Explain how the addition of a catalyst to a reaction can alter the activation energy.

Q6 - Calculation (3 marks)

If the activation energy of a reaction is 120 kJ mol^-1 and the temperature is increased from 25°C to 55°C, calculate the ratio of the rate constant at the higher temperature to the rate constant at the lower temperature. (Assume the Boltzmann constant is 8.314 J K^-1 mol^-1 and the R factor is approximately 2 for every 10°C rise in temperature.)

Q7 - Application (2 marks)

Explain how the size of reactant particles can affect the rate of a reaction according to collision theory.

Q8 - Knowledge Recall (1 mark)

State what is meant by an 'effective collision' in relation to collision theory.

Q9 - Calculation (3 marks)

If the average kinetic energy of reactant particles in a reaction at 25°C is 3.5 x 10^-21 J, calculate the percentage of reactant particles that have sufficient energy to overcome an activation energy of 80 kJ mol^-1. (Assume the Boltzmann constant is 8.314 J K^-1 mol^-1.)

Q10 - Application (2 marks)

Explain how the use of a homogeneous catalyst in a liquid reaction can lead to a faster rate of reaction compared to a heterogeneous catalyst.