What is the theoretical yield of CO2 if 5g of C4H4 is burned in sufficient O2?

Molar mass of C₄H₄ = (12.0×4 + 1.0×4) g/mol = 52 g/mol
Molar mass of CO₂ = (12.0 + 16.0×2) g/mol = 44 g/mol

C₄H₄ + 5O₂ → 4CO₂ + 2H₂O
Mole ratio C₄H₄ : CO₂ = 1 : 4

No. of moles of C₄H₄ burned = (5 g) / (52.0 g/mol) = .0962 mol
Theoretically, no. of moles of CO₂ formed = (.0962 mol) × 4 = 0.385 mol
Theoretical yield of CO₂ = (44.0 g/mol) × (0.385 mol) = 16.9 g

Balanced
C4H4 + 5O2 -> 4CO2 + 2H2O
This means that for one mole of C4H4 4 moles of CO2 is produced.
Have to convert 5g of C4H4 to moles then turn moles of CO2 back to grams.
Comment below if you get stuck

C4H4 + 5O2 --> 4CO2 + 2H2O. (Yes, every element must appear on both sides of the equation)

Now how many moles is 5 g of C4H4? Divide by the molar weight of C4H4 (52 g/mole)
Then multiply the number of moles of C4H4 by 4 to find how many moles of CO2 are made.
Usually, 'they' ask for the mass of CO2, so finally, multiply by the molar weight of CO2 to get the theoretical yield (in grams)