For the reaction A + B → C,it is found that doubling the concentration of A increases the rate by 4 times, and doubling the concentration of B doubles the reaction rate. What is the overall order of the reaction?

• 4

• 3/2

• 3

• 1

512.

Chemical reactions with very high E_a values are generally :

• very fast

• very slow

• moderately fast

• spontaneous

A radioactive isotope has a half-life of 10 days. If today 125 mg is left over, what was its original weight 40 days earlier?

• 2 gm

• 600 mg 

• 1 gm

• 1.5 gm

Which one of the following is a second order reaction?

• H₂ + Br₂ → 2HBr

• NH₄NO₃ → N₂ + 3H₂O

• H₂ + Cl₂ $\stackrel{\mathrm{sunlight}}{\to }$ 2HCl

• CH₃COOCH₃ + NaOH → CH₃COONa + H₂O

One mole of oxygen at 273 K and one mole of sulphur dioxide at 546 K are taken in two separate containers, then,

• kinetic energy of O₂ > kinetic energy of SO₂

• kinetic energy of O₂ < kinetic energy of SO₂

• kinetic energy of both are equal

• None of the above

The concentration of a reactant X decreases from 0.1 M to 0.005 Min 40 minute. If the reaction follows 1 order kinetics, the rate of the reaction when the concentration of X is 0.01 M will be :

• 1.73 × 10^-4 M min^-1

• 3.47 × 10^-4 M min^-1

• 3.47 × 10^-5 M min^-1

• 7.5 × 10^-5 M min^-1

For a reaction A+ B → C + D if the concentration of A is doubled without alterning the concentration of B, the rate gets doubled. If the concentration of B is increased by nine times without alterning the concentration of A, the rate gets tripled. The order of the reaction is :

• 2

• 1

• 3/2

• 4/3

2 g of a radioactive sample having half-life of 15 days was synthesised on 1^st Jan 2009. The amount of the sample left behind on 1^st March, 2009 (including both the days) is

• 0 gm

• 0.125 gm

• 1 gm

• 0.5 gm

For a chemical reaction A → B, the rate of the reaction is 2 × 10^-3 mol dm^-3 s^-1, when the initial concentration is 0.05 mol dm^-3. The rate of the same reaction is 1.6 × 10^-2 mol dm^-3 s^-1 when the initial concentration is 0.1 mol dm^-3. The order of the reaction is

• 2

• 0

• 3

• 1

The rate equation for a reaction A → B is r = k[A]⁰. If the initial concentration of the reactant is a mol dm³, the half-life period of the reaction is

• $\frac{\mathrm{a}}{2\mathrm{k}}$

• $\frac{\mathrm{k}}{\mathrm{a}}$

• $\frac{\mathrm{a}}{\mathrm{k}}$

• $\frac{2\mathrm{a}}{\mathrm{k}}$