Question

If you react 2.00 g of hydrogen completely using 15.87 g of oxygen to produce water, how much water (in grams) will you have?

Answer 1

Answer:

The amount (mass) of water we will have is 17.869 grams

Explanation:

The molar mass of hydrogen gas H₂ = 2.016 grams/mole

The molar mass of oxygen gas = 31.999 g/mol

Therefore, 2.00 g of hydrogen will give;

2.00/2.016 = 0.9921 moles of H₂ gas and

15.87 g of O₂ will give;

15.87/31.999 = 0.49595 moles

The reaction is as follows;

2H₂ (g) + O₂ (g) → 2H₂O (l)

Two moles of H₂ react with one mole of O₂ to produce two moles of H₂O

Therefore 0.9921 moles of H₂ will react with 0.9921/2 or 0.49595 moles of O₂ to produce 0.9921 moles of H₂O

From the above we note that all the H₂ and O₂ are completely consumed to form 0.9921 moles of H₂O

Molar mass of H₂O = 18.01528 g/mol

Number of moles = Mass/(Molar mass)

∴ Mass of H₂O = (Molar mass) × (Number of moles)

= 18.01528 g/mol × 0.9921 moles = 17.869 grams

Therefore the amount (mass) of water we will have = 17.869 grams.