Question

Calculate the total pressure in a $10.0L$ cylinder which contains $0.4g$ helium, $1.6g$ oxygen and $1.4g$ nitrogen at ${27}^{o}C$.

• A. $0.492atm$
• B. $49.2atm$
• C. $4.52atm$
• D. $0.0492atm$

Answer 1

The correct option is B $49.2atm$

The correct answer is D

Molar mass of $He=4.00g/mol=o.4g$

=$0.1mol$

Molar mass $O_2$= $32g/mol=1.6g$

= $1.6/32=0.05mol$

Molar mass $N_2$=$28g/mol$

=$1.4/28=0.05mol$

total mol gasses =$0.02mol$

we can calculate pressure in the cylinder using the gas law equation

$PV=nRT$

$p\times 10$=$0.20\times 0.82057\times 300$

$P=0.49$