For the two gaseous reactions, following data are given

           A → B;   k₁ = 10¹⁰ e^-20,000/T

           C → D;  k₂ = 10¹² e^-24,606/T

the temperature at which k₁ becomes equal to k₂

• 400 K

• 1000 K

• 800 K

• 1500 K

At 500 K, the half-life period of a gaseous reaction at an initial pressure of 80 kPa is 350 s. When the pressure is 40 kPa, the half-life period is 175 s. The order of the reaction is

• zero

• one

• two

• three

The radioactive isotope of caesium -137 of weight 8 g was collected on 1^st February, 2006 and kept in a sealed tube. On 1^st July 2006 it was found that only 0.25 g of it remained. The half-life period of the isotope is

• 37.5 day

• 30 day

• 25 day

• 50 day

The age of a specimen t is realted to the daughter/ parent ratio of number of atoms (D/ P) by the equation (λ = decay constant)

• t = $\frac{1}{\mathrm{\lambda }} \ln \left\{\frac{\mathrm{D}}{\mathrm{P}}\right\}$

• t = $\frac{1}{\mathrm{\lambda }} \ln \left\{1 + \frac{\mathrm{P}}{\mathrm{D}}\right\}$

• t = $\frac{1}{\mathrm{\lambda }} \ln \left\{2 + \frac{\mathrm{P}}{\mathrm{D}}\right\}$

• t = $\frac{1}{\mathrm{\lambda }} \ln \left\{1 + \frac{\mathrm{D}}{\mathrm{P}}\right\}$

Which one of the following set of units represents the smallest and largest amount of energy respectively?

• J and erg

• erg and cal

• cal and eV

• eV and lit-atom

For the reaction 2N₂O₅(g) → 4NO₂(g) + O₂(g) if he concentration of NO₂ increases by 5.2× 10^-3 M in 100 s then the rate of the reaction is 

• 1.3 × 10^-5 Ms^-1

• 0.5 × 10^-4 Ms^-1

• 7.6 × 10^-4 Ms^-1

• 2.5 × 10^-5 Ms^-1

A first order reaction is 10% complete in 20 min. The time taken for 19% completion is :

• 30 min

• 40 min

• 50 min

• 38 min

418.

The data for the reaction A + B → C

Ex.	[A]0	[B]0	Initial rate
1.	0.012	0.035	0.10
2.	0.024	0.070	0.80
3.	0.024	0.035	0.10
4.	0.012	0.070	0.80

The rate law corresponds to the above data is :

• rate = k [B]³

• rate = k [B]⁴

• rate = k[A] [B]³

• rate = k [A]² [B]²

A radioactive isotope has a half-life of 8 days. If today 125 mg is left over. What was its original weight 32 days earlier ?

• 6 g

• 5 g

• 4 g

• 2 g

The rate of a reaction is doubled for every 10° rise in temperature. The increase in reaction rate as a result of temperature rise from 10° to 100° is :

• 112

• 512

• 400

• 614