# What is the volume occupied by "10.23" moles of nitrogen gas at STP?

Jul 24, 2016

$\text{232.3 L}$

#### Explanation:

STP conditions are currently defined as a pressure of $\text{100 kPa}$ and a temperature of ${0}^{\circ} \text{C}$. The thing to remember about gases kept under STP conditions is that one mole of any ideal gas will always occupy $\text{22.71 L}$.

In other words, if you know how many moles of gas you have under STP conditions, you can use the molar volume of a gas, which is equal to ${\text{22.71 L mol}}^{- 1}$, as a conversion factor to help you find the volume occupied by the sample.

In your case, the sample contains $10.23$ moles of nitrogen gas kept under STP conditions. This means that the volume of the sample will be

10.23 color(red)(cancel(color(black)("moles N"_2))) * overbrace("22.71 L"/(1color(red)(cancel(color(black)("mole N"_2)))))^(color(blue)("molar volume of a gas at STP")) = color(green)(|bar(ul(color(white)(a/a)color(black)("232.3 L")color(white)(a/a)|)))

The answer is rounded to four sig figs.

SIDE NOTE More often than not, the definition of STP conditions will be given to you as a pressure of $\text{1 atm}$ and a temperature of ${0}^{\circ} \text{C}$.

Under these conditions, the molar volume of a gas is equal to ${\text{22.423 L mol}}^{- 1}$. If this is the definition given to you, simply redo the calculation using $\text{22.423 L}$ instead of $\text{22.71 L}$.