Reaction Kinetics

Given the following balanced equation :

2NO(g) + Cl₂(g) → 2NOCl(g)

If the rate of disappearance of Cl₂ is 4.84 x 10^-2 Ms^-1, what is the rate of disappearance of NO?

• 1.45 x 10^-2 Ms^-1

• 2.42 x 10^-2 Ms^-1

• 3.67 x 10^-2 Ms^-1

• 9.68 x 10^-2 Ms^-1

For second order reaction, the initial concentration of reactant A is 0.24 M. If the rate constant is 8.1 x 10^-2 M^-1 s^-1, what is the concentration of A after 29 seconds?

• 0.02 M

• 0.15 M

• 0.30 M

• 0.45 M

In the chemical reaction, the successful formation of products depends on the following factors EXCEPT:

• The collisions between reacting molecules must be effective

• The colliding molecules must approach each other in the right orientation

• The energy of colliding molecules must be equal to or more than activation energy

• A collision between molecules must produce sufficient energy to overcome the activation energy

Choose the correct statement regarding the changes occur to the activation energy (Ea), rate constant (k) and percentage yield when a catalyst is added to a chemical reaction.

• lower activation energy, k unchanged and % yield increased

• lower activation energy, k unchanged and % yield unchanged

• higher activation energy, k decreased and % yield increased

• higher activation energy, k unchanged and % yield unchanged

The reaction A + 2B → products was found to have the rate law, k = k[A][B]². Predict by what factor the rate of reaction will increase when the concentration of B is doubled and the concentration of A remained uncanged

• 2

• 4

• 6

• 8

The overall order for the reaction,

2A + B → C

is one and with respect to B the order is zero. Which of the following statements is true?

• The rate law of the reaction is rate =k[A]²[B]

• The formation of C is double the appearance of A

• The rate of reaction would increase with increasing concentration B

• The half-life of the reaction is independent on the concentration of the reactants

The catalyst alters the rate of a chemical reaction by,

• providing an alternative pathway with a lower Ea

• changing the products formed in the direction of the reaction

• providing a surface on which the molecules react

• increasing the frequencies of collisions between molecules

The first order rate constant for the decomposition of 0.5 M compound A at 100^oC is 0.03 min^-1. Calculate the half-life of A.

• 1.5 min

• 8.3 min

• 23.1 min

• 66.7 min

Which of the following statements about catalyst is true?

• It does not take part in the reaction

• It increase the yield of the reaction

• It provides an alternative mechanism for the reaction

• It increases the number of collisions between reacting molecules per second

What two factors govern whether a collision between reacting particles will be effective?

• orientation and potential energy 
• kinetic energy and temperature 
• kinetic energy and orientation 
• potential energy and kinetic energy