Step 1. Start with the balanced equation
"2C"_2"H"_2 + "5O"_2 → "4CO"_2 + "2H"_2"O"2C2H2+5O2→4CO2+2H2O
Step 2. Calculate the moles of "O"_2O2
"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"
