Consider this initial-rate data at a certain temperature for the reaction described by

2NOBr(g) => 2NO(g) +Br2(g)

image

Determine the value and units of the rate constant

k =

Concepts and reason

A rate law represents the behavior or nature of a reaction. It describes the relation between the rate of a reaction and the concentrations of reactants.

Fundamentals

Rate law for first order reaction is expressed by:

image

Here,k is the rate constant and n is the order of reaction.

Answer:

For the reaction,

image

The initial rates for formation of image are:

image

Consider the rate law; the rate of gas phase decomposition of

image

This Equation is directly proportional to the concentration of image.

Substitute the values image for r and 0.600 for reactant in the rate expression in equation 1 as follows:

image

Substitute the values image for r and 0.750 for reactant in the rate expression for equation 2 as follows:

image

The value and unit of rate constant is k is image

Substitute the values of first two equations in the rate expression then, divide the equation to carried out the order of reaction (n). Put the value of n in the first equation of rate expression and the value of k is carried out.