Consider the combustion reaction of acetylene (C2H2) :

2C2H2 + 5O2 (yields) 4CO2 + 2H2O

How many grams of carbon dioxide would be formed if 38.9 g C2H2 reacted completely with oxygen?

32.9 g CO2

46.0 g CO2

65.8 g CO2

131.0 g CO2

The answer to your question is  131 g of CO₂

Explanation:

Data

mass of CO₂ = ?

mass of C₂H₂ = 38.9 g

Balanced chemical reaction

                2C₂H₂  +  5O₂   ⇒   4CO₂   +   2H₂O

Process

1.- Calculate the molar mass of C₂H₂ and CO₂

molar mass C₂H₂ = (12 x 2) + (1 x 2) = 24 + 2 = 26 g

molar mass CO₂ = (12 x 1) + (16 x 2) = 12 + 32 = 44 g

2.- Use proportions to solve this problem.

                   2(26) g of C₂H₂ 4(44) g of CO₂

                    38.9 g of C₂H₂   x

                                 x = (38.9 x 4(44)) / 2(26)

                                 x = 6846.4 / 52

                                 x = 131.6 g of CO₂