Question

What is the volume, in liters, of 0.500 mol of `C_3H_8` gas at STP?

Answer 1

`color(blue)("11.2 L")`

Explanation:

Because we are at standard temperature and pressure and are given only one set of conditions, we can to use the ideal gas law equation:

I should mention that the pressure does not always have units of atm, it depends on the units of pressure given in the gas constant.

List your known and unknown variables.

`color(purple)("Knowns:"`
- Number of moles
- Temperature
- Pressure

`color(blue)("Unknowns:"`
Volume of `C_3H_8(g)`

At STP, the temperature is 273K and the pressure is 1 atm.

Let's rearrange the equation to solve for V:

`(nxxRxxT)/P`

`V = (0.500cancel"mol"xx0.0821Lxxcancel(atm)/cancel(molxxK)xx273cancelK)/(1cancel(atm)`

`V = 11.2 L`