Question

The total pressure after 200 seconds, if the initial pressure is $0.1$ atm is _______ .

• A. $0.154$ atm
• B. $0.248$ atm
• C. $0.174$ atm
• D. $0.114$ atm

Answer 1

The correct option is B $0.248$ atm

After 200 sec, $log\frac{P_o}{P}=\frac{kt}{2.303}=\frac{23.03\times {10}^{-3}\times 200}{2.303}=200\times {10}^{-2}=2.$
Hence, $\frac{P_o}{P}=100.$
or $P=P_o\times \mathrm{0.01.}$
The pressure of dinitrogen pentoxide is $P_{N_2{O}_5}=(P_o-2x)=P_o\times 0.01$
Hence, $x=\frac{1}{2}{P}_o(1-0.01)=0.495P_o=\mathrm{0.0495.}$
The total pressure is, $(P_o+3x)=P_o+3\times 0.0495=0.1+0.1485=0.2485atm.$