For the reaction `2N_(2)O_(5) rarr 4NO_(2)+O_(2)` rate of reaction and rate constant are `1.02 xx 10^(-4)` and `3.4 xx 10^(-5) sec^(-1)` respectively. The concentration of `N_(2)O_(5)` at that time will be

Options

A. `1.732`
B. `3`
C. `1.02xx10^(-4)`
D. `3.4xx10^(5)`

Answer

B

Explanation

The reaction
`2N_(2)O_(5)rar4NO_(2)+O_(2)`
is a first order reaction (Look at the unit of the unit of rate constant). Thus
Rate `=k[N_(2)O_(5)]`
`[N)_(2)O_(5)]=(Rate)/(k)`
`=(1.02xx10^(-4)molL^(-1_s^(-1))/(3.4xx10^(-5)s^(-1))`
`=3.0molL^(-1)`