Q1) Which of the following statements best defines chemical kinetics?

a) The study of the rates at which chemical reactions occur

b) The study of the energy changes during chemical reactions

c) The study of the equilibrium state of chemical reactions

d) The study of the structure of chemical compounds

Q2) What is the unit of reaction rate?

a) Molarity

b) Molarity per second

c) Moles per liter

d) Moles per liter per second

Q3) Which factor does NOT typically affect reaction rate?

a) Temperature

b) Pressure

c) Concentration

d) Catalysts

Q4) Which of the following is true for an exothermic reaction?

a) The activation energy decreases.

b) The products have higher energy than the reactants.

c) The reaction rate decreases with temperature.

d) The reaction releases heat to the surroundings.

Q5) What does the Arrhenius equation describe?

a) The relationship between reaction rate and temperature

b) The relationship between reactant concentration and reaction rate

c) The relationship between equilibrium constant and temperature

d) The relationship between activation energy and reaction rate

Q6) Which term describes the minimum energy required for a reaction to occur?

a) Activation energy

b) Potential energy

c) Kinetic energy

d) Gibbs free energy

Q7) A catalyst increases the rate of reaction by:

a) Increasing the activation energy

b) Decreasing the activation energy

c) Increasing the equilibrium constant

d) Decreasing the concentration of reactants

Q8) What does the rate constant (k) represent in a rate equation?

a) The rate of reaction

b) The concentration of reactants

c) The rate of product formation

d) The proportionality constant relating rate and concentration

Q9) Which of the following expressions represents the rate law for a second-order reaction?

a) Rate = k[A][B]

b) Rate = k[A]^2

c) Rate = k[A]

d) Rate = k

Q10) The rate of a reaction is found to double when the concentration of the reactant is doubled. What is the order of the reaction?

a) Zero order

b) First order

c) Second order

d) Third order

Q11) What is the half-life of a first-order reaction?

a) It is constant.

b) It varies with concentration.

c) It is inversely proportional to concentration.

d) It is directly proportional to concentration.

Q12) Which statement is true about a zero-order reaction?

a) The rate is independent of the concentration of the reactants.

b) The rate is directly proportional to the concentration of the reactants.

c) The rate increases exponentially with concentration.

d) The rate is inversely proportional to the concentration of the reactants.

Q13) The reaction A → B + C has a rate constant of 0.05 s^(-1). What is the rate of formation of B if the concentration of A is 0.1 M?

a) 0.005 M/s

b) 0.0025 M/s

c) 0.01 M/s

d) 0.05 M/s

Q14) Which factor does NOT affect the rate constant of a reaction?

a) Temperature

b) Catalyst

c) Concentration of reactants

d) Pressure

Q15) In a reaction, if the concentration of a reactant is tripled, and the rate increases by a factor of 9, what is the order of the reaction with respect to that reactant?

a) Zero order

b) First order

c) Second order

d) Third order

Q16) Which of the following represents a heterogeneous catalytic reaction?

a) 2A + B → C

b) A + B → C

c) A(g) → B(g)

d) A(s) → B(g)

Q17) The rate of a reaction is expressed in terms of which of the following?

a) Initial concentration of reactants

b) Final concentration of products

c) Rate constant

d) Change in enthalpy

Q18) A reaction has an activation energy of 50 kJ/mol. What happens to the rate of reaction if the temperature is increased?

a) The rate increases.

b) The rate decreases.

c) The rate remains constant.

d) The rate becomes zero.

Q19) Which statement about the rate-determining step in a reaction mechanism is correct?

a) It is always the first step of the mechanism.

b) It is the slowest step of the mechanism.

c) It involves the most stable intermediate.

d) It is unaffected by catalysts.

Q20) What is the effect of increasing the concentration of reactants on the rate of a reaction?

a) The rate increases.

b) The rate decreases.

c) The rate remains constant.

d) The rate becomes zero.