Which one of the following formula represents a first-order reaction?

Options

A. `K=(x)/(t)`
B. `K=(1)/(2t)[(1)/((a-x)^(2))-(1)/(a^(2))]`
C. `K=(2.303)/(t)log_(10).(a)/((a-x))`
D. `K=(1)/(t)(x)/(a(a-x))`

Answer

C

Explanation

For `1^(st)` order reaction
`k=(2.303)/(t)log_(10).(a)/((a-x))`