An ideal gas in a sealed container has an initial volume of 2.35 L. At constant pressure, it is cooled to to 18°C where its final volume is 1.75 L. What was the initial temperature?

Jan 3, 2018

391 K or 118 degrees Celsius

Explanation:

We use Charles' Law:
${V}_{1} / {T}_{1} = {V}_{2} / {T}_{2}$

Plug in the values:
$\frac{2.35 L}{T} _ 1 = \frac{1.75 L}{291 K}$

And don't forget to convert degrees Celsius to Kelvin! Just add 273.

Solve the algebra:
$2.35 L$ x $291 K$ = $683.85 L \cdot K$

$683.85 L \cdot K$ x $\frac{1}{1.75 L}$ = $391 K$

You can convert it back to degrees Celsius by subtracting 273.