• # question_answer A gaseous compound A reacts by three independent first-order processes (as shown in the figure) with rate constants $2\times {{10}^{-3}},\,3\times {{10}^{-3}}$ and $1.93\times {{10}^{-3}}{{s}^{-1}}$ products B, C and D respectively. If initially pure A  was taken in a closed container with P = 8 atm, then the partial pressure of B (in atm) after 100 s from start of experiment will be: A) 0.288                            B) 0.577        C) 1.154   D) None of these

 Overall rate constant = $k={{k}_{1}}+{{k}_{2}}+{{k}_{3}}=6.93\times {{10}^{-3}}$ ${{t}_{1/2}}=\frac{0.693}{6.93\times {{10}^{-3}}}=100s$ After half life, ${{P}_{B}}+{{P}_{C}}+{{P}_{D}}=4atm$ $\frac{{{P}_{B}}}{{{P}_{B}}+{{P}_{C}}+{{P}_{D}}}=\frac{{{k}_{1}}}{{{k}_{1}}+{{k}_{2}}+{{k}_{3}}}=\frac{200}{693}$ ${{P}_{B}}=4\times \frac{200}{693}=1.154\,atm$