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

1 Answer
Jul 24, 2016

Answer:

#"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"#.