posted by Beth .
If 20.0g acetylene is allowed to completeyl react with o@ how many g of O2 are reacted? 2C2H2 +5O2----4CO2 +2H20
1. Figure the moles of acetylene
Now look at the balanced equation. YOu need 5/2 moles of O2 for every one mole of acy. So you must need 5/2 * moles of acetylene. Now convert that to grams.