Question

What is the limiting reactant when 20g CH4 react with 15g H20?

Answer 1

Answer:

H₂O.

Explanation:

• It is clear from the balanced equation:

CH₄ + 2H₂O → CO₂ + 4H₂.

that 1.0  mole of CH₄ reacts with 2.0 moles of H₂O to produce 1.0 mole of CO₂ and 4.0 moles of H₂.

• To determine the limiting reactant, we should calculate the no. of moles of (20 g) CH₄ and (15 g) H₂O using the relation:

n = mass/molar mass

no. of moles of CH₄ = mass/molar mass = (20 g)/(16 g/mol) = 1.25 mol.

no. of moles of H₂O = mass/molar mass = (15 g)/(18 g/mol) = 0.833 mol.

• from the balanced reaction, 1.0  mole of CH₄ reacts with 2.0 moles of H₂O.

So, from the calculated no. of moles: 0.4167 mole of CH₄ reacts completely with 0.833 mole of H₂O and the remaining of CH₄ will be in excess.

So, the limiting reactant is H₂O.