Question

A $1.00L$ vessel containing $1.00g$ $H_2$ gas at ${27}^{o}C$ is connected to a $2.00L$ vessel containg $88.0g$ ${CO}_2$ gas, at also ${27}^{o}C$. When the gases are completely mixed, total pressure is?

• A. $20.525$ atm
• B. $4.105$ atm
• C. $16.420$ atm
• D. $730.69$ atm

Answer 1

Answer: (A)

$20.525$ atm

Given mass of H2=1 g

Moles of H2=$\frac{1}{2.016}=0.496$

Given mass of CO2=88 g

Moles of CO2=$\frac{88}{44}=2$

Total moles=2+0.496=2.496

Total volume=(1.00+2.00)l=3 l

According to Ideal gas equation,

pV=nRT

$p_{total}$=$\frac{2.496\times 0.0821\times 300}{3}=20.5$atm

$\frac{p_{H_2}}{p_{total}}=\frac{No.ofmolesofH2}{Totalmoles}{p}_{H_2}=\frac{0.496\times 20.5}{2.496}=4.07atm$

$\frac{p_{C{O}_2}}{p_{total}}=\frac{No.ofmolesofCO2}{Totalmoles}{p}_{C{O}_2}=\frac{2\times 20.5}{2.496}=16.4atm$

Total partial pressure=(16.4+4.07)atn=20.47 atm=20.5 atm