Question

A balloon has a volume of 0.5 L at 20°C. What will the volume be if the balloon is heated to 150°C?

Assume constant pressure and mass.

Answer 1

Assuming pressure is constant:

Explanation:

`V_1/T_1=V_2/T_2` (`T` in Kelvin)

`20^(o)C=20+273=293K`
`150^(o)C=150+273=423K`

`0.5/293=V_2/423->V_2=(0.5xx423)/293=0.72L`

Answer 2

The new volume will be `"0.7 L"`.

Explanation:

This is an example of Charles' law, sometimes called the temperature-volume law. It states that the volume of a gas is directly proportional to the Kelvin temperature, while pressure and amount are held constant.

The equation is `V_1/T_1=V_2/T_2`, where `V` is volume and `T` is temperature in Kelvins.

Known
`V_1="0.5 L"`
`T_1="20"^@"C"+273.15="293 K"`
`T_2="150"^@"C"+273.15="423 K"`

Unknown
`V_2`

Solution
Rearrange the equation to isolate `V_2`. Substitute the known values into the equation and solve.

`V_2=(V_1T_2)/T_1`

`V_2=((0.5"L"xx423"K"))/(293"K")="0.7 L"` rounded to one significant figure