Question

1. If you have 8.1 g CO₂ and 2.3 g H₂, which one is the limiting reactant. Show your work. 2. Calculate the theoretical yield of CH₄.

Answer 1

2.95 g of CH₄

Step-by-step explanation:

To start this, we determine the equation:

4H₂ + CO₂ → CH₄ + 2H₂O

4 moles of hydrogen react to 1 mol of carbon dioxide in order to produce 1 mol of methane and 2 moles of water.

To determine the limiting reactant, we need to know the moles of each reactant.

8.1 g . 1 mol/ 44g = 0.184 moles of carbon dioxide

2.3 g . 1mol / 2g = 1.15 moles of hydrogen

4 moles of hydrogen react to 1 mol of CO₂

Then, 1.15 moles may react to (1.15 . 1) /4 = 0.2875 moles

We only have 0.184 moles of CO₂, so this is the limiting reactant. Not enough CO₂ to complete the 0.2875 moles that are needed.

Ratio is 1:1. 1 mol of CO₂ produces 1 mol of methane

Then, 0.184 moles of CO₂ will produce 0.184 moles of CH₄

We convert moles to mass: 0.184 mol . 16 g /mol = 2.95 g