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

1 Answer
Jul 24, 2016

"232.3 L"

Explanation:

STP conditions are currently defined as a pressure of "100 kPa" and a temperature of 0^@"C". The thing to remember about gases kept under STP conditions is that one mole of any ideal gas will always occupy "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 "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 "1 atm" and a temperature of 0^@"C".

Under these conditions, the molar volume of a gas is equal to "22.423 L mol"^(-1). If this is the definition given to you, simply redo the calculation using "22.423 L" instead of "22.71 L".