The decomposition of `N_2 O_5` in carbon tetrachloride solution has been found to be first order with respect to `N_2 O_5` with rate constant, `k=6.2xx10^-4s^-1`
`N_2 O_5(G)rarr2NO_2(g)+1/2O_2(g)`
What concentration of `N_2 O_5` would give a rate of `4.2xx10^-3 mol L^-1 s^-1`?

Explanation

`N_2O_5(sol,)overset(Cl_4)(rarr)2NO_2(sol)+1/2O_2(g)`
Rate=`k[N_2O_5]`
(a) Here k`=6.2xx10^(-4)s^(-1),[N_2O_5]`
`=2.50" mol L"^(-1)`
`therefore` Rate=`6.2xx10^(-4)s^(-1)xx2.50" mol L"^(-1)`
`=1.55xx10^(-3)" mol L"^(-1)s^(-1)`
(b) Rate=`4.2xx10^(-3)" mol L"^(-1)s^(-1)`
`[N_2O_5]=?`
`[N_2O_5]=("Rate")/(k)=(4.2xx10^(-3)" mol L"^(-1)s^(-1))/(6.2xx10^(-4)s^(-1))`
=6.77 mol `L^(-1)`