Which of the following graphs represent a first order reaction (a=initial concentration of reactant, x=concentration of reactant consumed, t=time)

Options

A. `(i),(ii),(iv)`
B. `(iii), (iv)`
C. `(ii), (iii)`
D. `(i),(ii)`

Answer

A

Explanation

For a first order reaction
Rate `=- (Delta [A])/(Delta t)=k [A]`
It is a straight line plot with negative slope when cocentration of reactant is considered as in (i) and half-life for first order is independent from concentration, as in plot (ii).`