# A sample of Freon-12 (CF_2Cl_2) occupies 25.5 L at 298 K and 153.3 kPa. How do you find its volume at STP?

May 23, 2018

${V}_{S T P} = 35.3 L$

#### Explanation:

Using the combined gas law...

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

Solve for ${V}_{2}$ ...

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

${P}_{1} = 153.3 \text{KPa} \textcolor{w h i t e}{\times x} {P}_{2} = 101.325 K P a$
V_1=25.5Lcolor(white)(xxxxxx)V_2=?
T_1=298K"color(white)(xxxxxx)T_2=273K

${V}_{2} = \frac{25.5 L \cdot 153.3 \cancel{K P a} \cdot 273 \cancel{K}}{101.325 \cancel{K P a} \cdot 298 \cancel{K}} = 35.3 L$