Question #24fe2
1 Answer
Explanation:
The idea here is that you need to use the ideal gas law to determine how many moles of gas you have in that sample.
Once you know how many moles you get in
So, the ideal gas law equation looks like this
#PV = nRT" "# , where
Rearrange this equation to find the number of moles of gas you have in that sample under those specific conditions for pressure and temperature
#n = (PV)/(RT)#
#n = (1.30color(red)(cancel(color(black)("atm"))) * 825 * 10^-3color(red)(cancel(color(black)("L"))))/(0.082(color(red)(cancel(color(black)("atm"))) * color(red)(cancel(color(black)("L"))))/("mol" * color(red)(cancel(color(black)("K")))) * (273.15 + 19)color(red)(cancel(color(black)("K")))) = "0.04477 moles"#
The molar mass of a substance tells you what the mass of one mole of that substance is. In yur case, you have
#M_"M" = m/n#
#M_"M" = "0.742 g"/"0.04477 moles" = "16.57 g/mol"#
I'll leave the answer rounded to three sig figs
#M_"M" = color(green)("16.6 g/mol")#