The plot of concentration of the reactant vs time for a reaction is a straight line with a negative slope. This reaction follows

Options

A. zero order reaction
B. first order reaction
C. second order reaction
D. third order reaction

Answer

A

Explanation

Consider the zero order reaction
`R to P`
Rate = `(d[R])/(dt) = k [R]^(@)`
As any quantity raised to power zero is unity, we have
Rate `= (-d[R])/(dt) = k xx 1`
or `d [R] = - k dt`
Integrating both rides
`[R] = - kt + I.C`
Where I.C. is the constant of integration.
At t = 0 the concentration of the reactant. `R = [R]_(0)`, where
`[R]_(0)` is initial concentration of the reactant. Subtituting this result in the above equation, we get
`[R]_(0) = - k xx 0 + I.C`
`[R]_(0) = I.C`
Thus, `[R] = - kt + [R]_(0)`
Comparing it with equation of a straight line, `y = mx + c`, if we plot `[R]` against t, we get a straight line with slope = - K are intercept equal to `[R]_(0)`