Question

The plot of concentration of a reactant vs time for a chemical reaction is shown below.

The order of this reaction with respect to the reactant is

(a) 0

(b) 1

(c) 2

(d) not possible to determine from this plot

Answer 1

Answer is : (a) 0

For a reaction

X → Y,

rate = − d[X]/dt; [X] = concentration of X.

If reaction is nth order, 

rate ∝ [X]ⁿ

From the graph, the slope d[X]/dt is constant.

∴ Rate is constant at any concentration.

∴ n = 0