\(NO_2\) required for a reaction is produced by decomposition of \(N_2 O_5\) in \(CCl_4\) as by equation
\(2N_2 O _ {5 (g)} \rightarrow 4 NO _ {2 (g)} +O_{2(g)}\)
The initial concentration of \(N_2 O _5\) is 3 mol \(L^{-1}\) and it is 2.75 mol \(L^{-1}\) after 30 minutes.
The rate of formation of \(NO_2\) is x \(\times 10^{-3}\) mol \(L^{-1} \,min ^{-1},\) value of x is ________.