Question

Hydrogen gas and oxygen gas react to make water in 62% yield. If 100. g of hydrogen gas reacted with excess oxygen gas calculate the actual yield of water in grams.

Answer 1

Hydrogen gas reacted with Oxygen gas to produce Water molecule.

Reaction equation is H₂(g) + O₂(g) H₂O .

Balanced equation is,

2H₂ + O₂ 2H₂O

Oxygen used in excess, hence hydrogen is limiting reagent.

Mol wt of Hydrogen = 2.0, hence moles of H₂ = wt in grams / mol wt. = 100 / 2 = 50 moles of H₂

2 molecules of H₂ gave 2 molecules of water. hence ratio is 1:1.

By considering 100% yield, moles of H₂O = 50 moles

Mol wt. of Water= 18.0, hence weight of H₂O produce = moles X mol wt. = 50 X 18 = 900 grams of H₂O.

This reaction gave only 62% yield,

Hence wt of water produced = 900 X 62 / 100 = 558 grams

Hence Actual yield of H₂O in grams = 558 g