Question

Calculate the volume of carbon dioxide gas lost at 25 degrees and 100kPa?

Initial mass (g) = 125.5
Final mass (g) = 124.8
Change in mass (g) = 0.7

Answer 1

`0.38L`, or `380cm^3` lost.

Explanation:

Use the Ideal Gas Law:

`PV=nRT`

For the initial mass of `CO_2`:

Remember, the formula for moles, `n`, is `n=m/M`, where `m` is the given mass and `M` the molar mass.

`M=44.01g/("mol")`

Here, `m=125.5g`.

So `n=125.5/44.01=2.85"mol"`.

So now, we can rearrange the gas law:

`V=(nRT)/P`

`V=(2.85*8.314*298.15)/100`

`V=70.65L` of carbon dioxide before the loss.

For the final mass of `CO_2`:

Here, `m=124.8g`

So `n=124.8/44.01=2.835"mol"`

`V=(nRT)/P`

`V=(2.835*8.314*298.15)/100`

`V=70.27L` of carbon dioxide after loss.

Therefore, the total loss must be `V_"final"-V_"initial"`.

So the loss is equal to `70.65-70.27=0.38L`.