# 720 mL of H_2 gas at 0 degree C and 126.6 kPa is changed to S .T. P. What will be its new volume?

Jan 10, 2017

The new volume will be 907 mL.

#### Explanation:

STP is defined as 0 °C and 1 bar (100 kPa).

Since only the pressure changes, we can use Boyle's Law to solve the problem.

Boyle's Law is

$\textcolor{b l u e}{\overline{\underline{| \textcolor{w h i t e}{\frac{a}{a}} {P}_{1} {V}_{1} = {P}_{2} {V}_{2} \textcolor{w h i t e}{\frac{a}{a}} |}}} \text{ }$

We can rearrange Boyle's Law to get

V_2 = V_1 × P_1/P_2

In this problem,

${P}_{1} = \text{126 kPa"; V_1 = "720 mL}$
${P}_{2} = \text{100 kPa"; V_2 = "?}$

${V}_{2} = \text{720 mL" × (126 color(red)(cancel(color(black)("kPa"))))/(100 color(red)(cancel(color(black)("kPa")))) = "907 mL}$