Question #5018b

1 Answer
Apr 22, 2017

Answer:

#"16.0 g"#

Explanation:

STP conditions are usually given as a pressure of #"1 atm"# and a temperature of #0^@"C"#. Under these conditions, #1# mole of any ideal gas occupies #"22.4 L"# #-># this is known as the molar volume of a gas at STP.

Using the molar volume of a gas at STP, you can calculate the number of moles of oxygen gas present in your sample

#11.2 color(red)(cancel(color(black)("L"))) * "1 mole O"_2/(22.4color(red)(cancel(color(black)("L")))) = "0.50 moles O"_2#

To convert this to grams, use the molar mass of oxygen gas

#0.50 color(red)(cancel(color(black)("moles O"_2))) * "32.0 g"/(1color(red)(cancel(color(black)("mole O"_2)))) = color(darkgreen)(ul(color(black)("16.0 g")))#

The answer is rounded to three sig figs, the number of sig figs you have for the volume of oxygen gas.