Following mechanism has been proposed for a reaction,

2A+B  $\iff$ D+E

A+B$\to$ C+D    ...(Slow)

A+ C$\to$ E         ...(Fast)

The rate law expression for the reaction is:

(a) r = K[A]²[B]

(b) r=K[A][B]

(c) r= K[A]²

(d) r= K[A][C]

For the reaction N₂ + 3H₂ $\to$ 2NH₃, the rate $\frac{\mathrm{d}\left[{\mathrm{NH}}_3\right]}{\mathrm{dt}}$ = 2x10^-4 Ms^-1 .Therefore, the rate $-\frac{\mathrm{d}\left[{\mathrm{N}}_2\right]}{\mathrm{dt}}$ is given as:

(1) 10^-4 Ms^-1

(2) 10⁴ Ms^-1

(3) 10^-2 sM^-1

(4) 10^-4 sM^-1

If 'a' is the initial concentration of a substance which reacts according to zero order kinetics and K is rate constant, the time for the reaction to go to completion is:

(a) a/K

(b) 2/Ka

(c) K/a

(d) 2K/a

In a reaction, the rate expression is, rate = K[A][B]^2/3[C]⁰ , the order of reaction is:

1. 1

2. 2

3. 5/3

4. zero

The rate of a reaction get doubles when the temperature changes from 7°C to 17°C. By what factor will it change for the temperature change from 17°C to 27°C?

(a) 1.81

(b) 1.71

(c) 1.91

(d) 1.76

For the elementary step,

(CH₃)_3.CBr(aq) → (CH₃)₃C⁺ (aq) + Br^- (aq) the molecularity is:

(a) zero

(b) 1

(c) 2

(d) cannot ascertained

When ethyl acetate was hydrolysed in pressure of 0.1 N HCl, the rate constant was found to be 5.40 x 10^-5 sec^-1 . But when 0.1 N H₂SO₄ was used for hydrolysis, the rate constant was found to be 6.25 X10^-5sec^-1. Thus, it may be concluded that:

(1) H₂SO₄ is stronger than HCI

(2) H₂SO₄ is weaker than HCl

(3) H₂SO₄ and HCl both have the same strength

(4) the data are not sufficient to compare the strength of H₂SO₄ and HCI

The half time of a second order reaction is:

(1) inversely proportional to the square of the initial concentration of the reactants

(2) inversely proportional to the initial concentration of the reactants

(3) proportional to the initial concentration of reactants

(4) independent of the initial concentration of reactants

The half-life period of a first order chemical reaction is 6.93 minutes. The time required for the completion of 99% of the chemical reaction will be (log 2 = 0.301):

(a) 23.03 minutes

(b) 46.06 minutes

(c) 460.6 minutes

(d) 230.3 minutes

A zero order reaction is one:

(1) In which reactants do not react

(2) In which one of the reactants is in large excess

(3) Whose rate does not change with time

(4) Whose rate increases with time