Which of the following statement is not correct?

• In zero order reaction the rate of the reaction remains constant throughout

• A second order reaction would become a pseudo first order reaction when one of the reactants is taken in large excess

• The value of first order rate constant expends on the units of the concentration terms used

• In a first order reaction the plot of log (a - x) vs time gives a straight line

The number of α and β particles emitted in the chain of reactions leading to the decay of ${}_{92}{}^{238}$U to ${}_{82}{}^{206}$Pb :

• 8 β particles and 6 α particles

• 5 α particles and O β particles

• 8 α and 6 β particles 

• 10 α particles and 10 β  particles

The disintegration constant of radium with half-life 1600 yr is

• 2.12 × 10^-4 yr^-1

• 4.33 × 10^-4 yr^-1

• 3.26 × 10^-3 yr^-1

• 4.33 × 10^-12 yr^-1

Consider the folowing reaction,

A → Products

This reaction is completed in 100 mins. The rate constant of this reaction at t₁ = 10 min is 10^-2 min^-1. What is the rate constant (in min^-1) at t₂ = 20 min.

• 2 × 10^-2

• 10^-2

• 5 × 10^-3

• 0.1

Consider the following reaction,

N₂(g) + 3H₂(g) → 2NH₃(g)

The rate of this reaction in terms of N₂ at T K is $\frac{-\mathrm{d} \left[{\mathrm{N}}_2\right]}{\mathrm{dt}}$ = 0.02 mol L^-1s^-1. What is the value of -d[H₂]/ dt (in units of mol L^-1s^-1) at the same temperature.

• 0.02

• 50

• 0.06

• 0.04

10 g of a radioactive element is disintegrated to 1 g in 2.303 minutes.What is the half-life (in minutes) of that radioactive element?

• 1/ 0.693

• 6.93

• 1

• 0.693

Which one of the following equation is correct for the reaction?

 N₂(g) + 3H₂(g) → 2NH₃ (g)?

• $3\frac{\mathrm{d}\left[{\mathrm{NH}}_3\right]}{\mathrm{dt}}=2\frac{\mathrm{d}\left[{\mathrm{H}}_2\right]}{\mathrm{dt}}$

• $3\frac{\mathrm{d}\left[{\mathrm{NH}}_3\right]}{\mathrm{dt}}=3\frac{\mathrm{d}\left[{\mathrm{H}}_2\right]}{\mathrm{dt}}$

• $2\frac{\mathrm{d}\left[{\mathrm{NH}}_3\right]}{\mathrm{dt}}= -3\frac{\mathrm{d}\left[{\mathrm{H}}_2\right]}{\mathrm{dt}}$

• $3\frac{\mathrm{d}\left[{\mathrm{NH}}_3\right]}{\mathrm{dt}}= -2\frac{\mathrm{d}\left[{\mathrm{H}}_2\right]}{\mathrm{dt}}$

......... of a reaction cannot be determined experimentally.

• Order

• Rate

• Rate constant

• Molecularity

Assertion (A) - At 300 K, kinetic energy of 16 g of methane is equal to the kinetic energy of 32 g of oxygen.

Reason (R) - At constant temperature, kinetic energy of one mole of all gases is equal.

The correct answer is 

• Both (A) and (R) are true and (R) is the correct explanation of (A)

• Both (A) and (R) are true but (R) is not the correct explanation of (A).

• (A) is true but (R) is not true.

• (A) is not true but (R) is true

The half-lives of two radioactive nuclides A and B are 1 and 2 min respectively. Equal weights of A and B are taken separately and allowed to disintegrate for 4min. What will be the ratio of weights of A and B disintegrated?

• 1:2

• 5:4

• 1:2

• 1:3