Question

We allow 24.0 g of CH4 to react as completely as possible with excess O2, to form CO2 and H2O . Write the balanced equation for this question . What mass of O2 reacts?

Answer 1

CH4 + 2O2 ==> CO2 + 2H2O
mols CH4 = grams/molar mass = ?
Using the coefficients in the balanced equation, convert mols CH4 to mols O2.
Then g O2 = mols O2 x molar mass O2 = ?

Answer 2

24.0g CH4 * 1mol CH4/16.04gCH4 * 1mol O2/1molCH4 = 1.5 MOL O2