# A sample of hydrogen has a volume of 1107 mL when the temperature is 101.9 degC and the pressure is 0.867 atm. What will be the volume of the gas at STP?

Jun 20, 2016

$\frac{{P}_{1} {V}_{1}}{T} _ 1 = \frac{{P}_{2} {V}_{2}}{T} _ 2$

#### Explanation:

So what is $\text{STP}$? Standards differ across curricula. I use the IUPAC standard of $273.15 \cdot K$, and $0.98692 \cdot a t m$. (The pressure is this absurd value because this represents $100 \cdot k P a$. Chemists usually prefer to work in $\text{atmospheres}$, as this may be directly measured in a laboratory with a mercury column.)

For the calculation, ${V}_{2}$ $=$ $\frac{{P}_{1} \cdot {V}_{1} \cdot {T}_{2}}{{T}_{1} \cdot {P}_{2}}$

$=$ $\frac{0.867 \cdot a t m \times 1107 \cdot m L \times 273.15 \cdot K}{375.1 \cdot K \times 0.987 \cdot a t m}$

$=$ ??mL

Clearly, the expression gives an answer in $m L$, as is required for a volume.