Answer:
The correct answer is 33 g CO₂
Explanation:
The reaction between CH₄ and O₂ is a combustion reaction. The complete combustion reaction is described by the following chemical equation:
CH₄(g) + 2 O₂(g)→ CO₂(g) + 2 H₂O(g)
16 g 64 g 44 g 36 g
That means that 1 mol of CH₄ (equal to 16 g) reacts with 2 moles of O₂ (65 g) to give 1 mol of CO₂ (44 g) and 2 moles of H₂O (36 g).
In order to calculate the grams of CO₂ produced by the reaction, we have to figure out which is the <em>limiting reactant</em>. For this, we can choose one reactant and calculate how many grams we need of the other reactant by using the quantity of reactant we have. Let's choose CH₄. According to the chemical equation, 16 g of CH₄ reacts with 64 g of O₂. If we have 12 g, the quantity of O₂ we need is the following:
g O₂ requested = 12 g CH₄ x (64 g O₂)/(16 g CH₄) = 48 g
We need 48 g of O₂ and we have 133 g, so the O₂ is the excess reactant and CH₄ is the limiting reactant. With the limiting reactant, we calculate the amount of product produced. According to the chemical equation, with 16 g of CH₄ we obtain 44 g of CO₂. We have 12 g, so we multiply the grams of CH₄ we have by the factor 44 g CO₂/16 g CH₄:
grams of CO₂ produced = 12 g CH₄ x 44 g CO₂/16 g CH₄ = 33 g CO₂
