Chemistry Test ...

The half life of a first order reaction is 2000 years. If the concentration after 8000 years is 0.02M, then the initial concentration was:

For a reaction A → B, enthalpy of reaction is −4.2kJmol⁻¹ and enthalpy of activation is 9.6kJmol⁻¹. The correct potential energy profile for the reaction is shown in option.

The rate constant for a first order reaction is 4.606 × 10⁻³s⁻¹. The time required to reduce 2.0 g of the reactant to 0.2g is:

If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by

A first order reaction has a rate constant of 2.303× 10⁻³s⁻¹. The time required for 40gof this reactant to reduce to 10g will be [ Given that log₁₀2 = 0.3010]

The correct difference between first and second order reactions is that

Mechanism of a hypothetical reaction X₂ + Y₂ → 2XY, is given below :

(i) X₂ ⇌ X + X (fast)

(ii) X + Y₂ → XY + Y (slow)

(iii) X + Y → XY (fast)

The overall order of the reaction will be

Rate of a reaction can be defined as

Order of reaction can be

The geometry of hydronium ion is