# A container containing 5.00 L of a gas is collected at 100 K and then allowed to expand to 20.0 L. What must the new temperature be in order to maintain the same pressure?

Apr 3, 2017

400 Kelvin (K).

#### Explanation:

We are given the initial volume and initial temperature (in Kelvins, so no need to convert from Celsius to Kelvin). We are also given the final volume.

In short, we have:

${V}_{1}$: 5.00 L
${T}_{1}$: 100 K

${V}_{2}$: 20.0 L
${T}_{2}$: ?

Charles' Law:

${V}_{1} / {T}_{1}$=${V}_{2} / {T}_{2}$

We have 3 of the 4 variables, and if we fill those in, we have...

$\frac{5.00}{100}$=$\frac{20.0}{T} _ 2$

Using the algebra skill of cross multiplying, we can get...

5.00${T}_{2}$=2000

Dividing both sides by 5.00 to isolate the ${T}_{2}$, we get...

${T}_{2}$= 400. K

It is 400. due to the significant figure rule.