551.

For the decomposition reaction of lime stone, the correct expression for rate constant, K_P is

• ${\mathrm{K}}_{\mathrm{p}} = \frac{{\mathrm{p}}_{\mathrm{CaO}}.{\mathrm{p}}_{{\mathrm{CO}}_2}}{{\mathrm{p}}_{{\mathrm{CaCO}}_3}}$

• ${\mathrm{K}}_{\mathrm{p}} = \frac{\left[\mathrm{CaO}\right]\left[{\mathrm{CO}}_2\right]}{\left[{\mathrm{CaCO}}_3\right]}$

• ${\mathrm{K}}_{\mathrm{p}} = \frac{{\mathrm{p}}_{\mathrm{CaO}} + {\mathrm{p}}_{{\mathrm{CO}}_2}}{{\mathrm{p}}_{{\mathrm{CaCO}}_3}}$

• K_p = p_CO2

Decomposition of H₂O₂ is a first order reaction. Initially, solution of H₂O₂ having half-life time 15 min is 16 volume. When solution becomes 1 volume

• 4 min

• 15 min

• 30 min

• 60 min

What is the two third life of a first order reaction having k = 5.48 × 10^-14s^-1?

• 1 × 10¹³ s

• 2 × 10¹³ s

• 8 × 10¹³ s

• 5 × 10¹⁴ s

At room temperature, the reaction between NO and O₂ to give NO₂ is fast while that of between CO and O₂ is slow. It is because

• the intrinsic energy of the reaction 2NO + O₂ $\rightleftharpoons$ 2NO₂ is less

• CO is smaller in size than that of NO

• CO is poisonous

• the activation energy for the reaction 2 NO + O₂ $\rightleftharpoons$ 2NO₂ is less

A radioactive isotope having a half-life of 3 days was received after 12 days. It was found that there were 3 g of the isotope in the container. Find the initial weight of the isotope, when it was packed (antilog 1.203 = 16)

• 12 gm

• 24 gm

• 36 gm

• 48 gm

Transition state 2 (TS2) is structurally most likely as a/an

• intermediate 2

• product

• intermediate 1

• transition state 3(TS3)

Which graph shows zero activation energy for reaction?

Which of the following is correct for a first order reaction?

• t_1/2 ∝ a°

• t_1/2  ∝ a²

• t_1/2  ∝ a

• t_1/2  ∝ 1/a

During nuclear explosion one of the products is ⁹⁰Sr with half-life of 28.1 yr. If 1 μg of ⁹⁰Sr was absorbed in the bones of a newly born body instead of calcium, how much of it will remain after 60 yr, if it is not lost metabolically?

• 0.184 μg

• 0.025 μg

• 0.262 μg

• 0.228 μg

The half-life period of a radioactive element is 30 days. After 90 days, which of the following quantity will be left?

• 1/2

• 1/6

• 1/8

• 1/4