# If 9 L of a gas at room temperature exerts a pressure of 12 kPa on its container, what pressure will the gas exert if the container's volume changes to 4 L?

Jul 24, 2016

color(purple)("27 kpa"

#### Explanation:

Let's identify our knowns and unknowns:

The first volume we have is $9 L$, the first pressure is $12 k P a$, and the second volume is $4 L$. Our only unknown is the second pressure.

We can ascertain the answer using Boyle's Law:

Rearrange the equation to solve for ${P}_{2}$

We do this by dividing both sides by ${V}_{2}$ in order to get ${P}_{2}$ by itself:
${P}_{2} = \frac{{P}_{1} \times {V}_{1}}{V} _ 2$

Now all we have to do is plug in the given values:
${P}_{2} = \left(12 \setminus k P a \times 9 \setminus \cancel{\text{L")/(4\cancel"L}}\right)$ = $27 k P a$