Question

For the reaction ?CH4+ ?O2 ==> ?CO2+ ?H2O, what is the maximum amount of CO2 (44.0095 g/mol) which could be formed from 3.67 g of CH4 (16.0425 g/mol) and 4.23 g of O2 (31.9988 g/mol)? Answer in units of g

I know that you have to balance the equation, so the coefficients 1, 2, 1, and 2, respectively, but I'm not sure what to do after that.

Answer 1

Yes, CH4 + O2 ==> CO2 + 2H2O

This is a limiting reagent (LR) problem and you know that because amounts are given for BOTH reactants.
mols CH4 = grams/molar mass
mols O2 = grams/ molar mass

Using the coefficients in the balanced equation convert mols CH4 to mols CO2.
Do the same to convert mols O2 to mols CO2.
It is likely that the two values will not agree which means one of them is wrong; the correct value in LR problem is ALWAYS the smaller one and the reagent producing the smaller value is the LR.

Now convert mols CO2 to grams. mol x molar mass = grams.

Answer 2

Thank you!