Step 1. Start with the balanced equation
#"2C"_2"H"_2 + "5O"_2 → "4CO"_2 + "2H"_2"O"#
Step 2. Calculate the moles of #"O"_2#
#"Moles of O"_2 = 5.00 color(red)(cancel(color(black)("g O"_2))) × "1 mol O"_2/(32.00 color(red)(cancel(color(black)("g O" _2)))) = "0.1562 mol O"_2#
Step 3. Calculate the moles of #"CO"_2#
#"Moles of CO"_2 = 0.1562 color(red)(cancel(color(black)("mol O"_2))) × "4 mol CO"_2/(5 color(red)(cancel(color(black)("mol O"_2)))) = "0.1250 mol O"_2#
Step 4. Use the Ideal Gas Law to calculate the moles of #"CO"_2#
The Ideal Gas Law is
#color(blue)(bar(ul(|color(white)(a/a)pV = nRTcolor(white)(a/a)|)))" "#
where
- #p# is the pressure
- #V# is the volume
- #n# is the number of moles
- #R# is the gas constant
- #T# is the temperature
We can rearrange the Ideal Gas Law to get
#V = (nRT)/p#
STP is 1 bar and 0 °C.
#V = (0.1250 color(red)(cancel(color(black)("mol"))) × "0.083 14" color(red)(cancel(color(black)("bar")))·"L"·color(red)(cancel(color(black)("K"^"-1""mol"^"-1"))) × 273.15 color(red)(cancel(color(black)("K"))))/(1 color(red)(cancel(color(black)("bar")))) = "2.84 L"#
