Multiple Choice Questions (MCQs): Chemical Kinetics - 1 - NEET MCQ

Order of a reaction is experimentally determined quantity so it can be negative fractional or zero.

For 1st order reaction half life is independent of initial concentration of reactant.

k = A exp(-kt)

If activation energy is high rate of reaction will decrease and reaction will be slow.

The minimum energy that the colliding molecules must possess for the chemical reaction to occur is known as threshold energy.
The extra energy required by a reactant to participate in a reaction is called activation energy.

Rate law states that rate of reaction is dependent on concentration of reactant raise to power order of reaction.

Rate constant is also known as velocity constant.

Carbon – 14 is used in determining the age of organic substances

Inhibitors inhibits the action of catalyst and hence slows down the rate of reaction.

Catalyst doesnot change the equilibrium constant it only helps in reaching the equilibrium at a faster rate.

The time taken for half the reaction to complete, i.e., the time in which the concentration of a reactant is reduced to half of its original value is called half-life period of the reaction. But it is impossible to perform 100% of the reaction. Whole of the substance never reacts because in every half-life, 50% of the substance reacts. Hence, time taken for 100% completion of a reaction is infinite. 

Collision theory is only applicable to bimolecular reaction.

Rate of reaction is dependent on concentration of reactant

The correct answer is Option C.

Let R be the rate of reaction.
For first order reaction,
R=K[A]¹
⇒K=R[A]^-1
Whereas, K and [A] are rate constant and initial concentration of reactant respectively.
Therefore,
Unit of rate constant =(mol L^-1)^1-nsec^-1
For first order reaction, n=1
Unit of rate constant = sec^-1
Hence the unit of rate constant for first order reaction is sec^-1.

Elementary reaction are one step reactions.

Rate constant is independent of concentration of reactant.

In acid catalysed hydrolysis of ethylacetate the water is in excess so it is pseudo 1st order reaction.

Decomposition of N₂O₅ is 1st order reaction.

As rate k = [RCl] , on decreasing the concentration of RCl to half , the rate will also be halved . Rate will also increase with temperature.

Photochemical reaction between H₂ and Cl₂ is 0 zero wrt to reactants.

Temperature coefficient is the factor by which the rate constant of a reaction increase with increase in temperature by 10°C. It lies between 2 and 3.

Rate of reaction is determined by slowest step.