121.

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

Observe the following reaction 2A + B → C. The rate of formation of C is 2.2 × 10^-3 mol L^-1min^-1. What is the value of - $\frac{\mathrm{d}\left[\mathrm{A}\right]}{\mathrm{dt}}$ (in mol L^-1min^-1)?

• 2.2 × 10^-3 

• 1.1 × 10^-3 

• 4.4 × 10^-3 

• 5.5  × 10^-3 

The rate constant of a first order reaction at 27°C is 10^-3 min^-1. The temperature coefficient of this reaction is 2. What is the rate constant (in min^-1 ) at 17°C for this reaction ?

• 10^-3

• 5 × 10^-4

• 2 × 10^-3

• 10^-2

What is the temperature at which the kinetic energy of 0.3 moles of helium is equal to the kinetic energy of 0.4 moles of argon at 400 K?

• 400 K

• 873 K

• 533 K

• 300 K