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

Tags

NGSS.HS-PS1-5

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

Tags

NGSS.HS-PS1-7

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

Tags

NGSS.HS-PS1-5

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

Tags

NGSS.HS-PS1-5

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

Tags

NGSS.HS-PS1-4

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

Tags

NGSS.HS-PS1-5

The rate constant for a second order reaction at 30^oC is 2.0 x 10^-6 M^-1s^-1. The activation energy for this is 108 kJ mol^-1. By using Arrhenius equation, determine the collision frequency factor, A for the reaction.

• 5.0 x 10¹²

• 6.0 x 10¹²

• 8.0 x 10¹²

• 1.0 x 10¹³

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