• Data

Mass of hydrogen peroxide (H2O2) = 12g
Molar mass of hydrogen peroxide (H2O2) = 34g/mole
Molar volume at S.T.P = 22.4dm3/mole
i. The volume of water formed.
ii. The volume of oxygen formed.
• Convert 12g of H2O2 into mole

Mole = mass / Molar mass
= 12g / 34g/mole
= 0.3529411765 mole of H2O2
• i. Find the volume of water formed.

The chemical equation for the reaction

2(H2O2)(g) catalase 2H2(l) + O2(g) catalyst

Make mole equivalent between H2O2 and water (H2O)

2 moles of (H2O2) Ξ 2 moles of H2O
0.3529 moles of (H2O2) Ξ ?? of H2O

= (0.3529 mole × 2 mole) / 2 moles
= 0.352941179 mole of H2O

Convert 0.352941176 of H2O into volume

Volume = mole × molar volume
= 0.352941176 mole × 22.4dm3/mole
= 7.9dm3

7.9dm3 of water was formed at S.T.P

• ii/ Calculate the volume of oxygen gas formed

use the mole of H2O2 with that of O2

2 moles of H2O2 Ξ 1 mole of O2
0.3529 mole of H2O2 Ξ ?? of O2

X = (0.3529 mole × 1 mole) / 2 moles
= 0.17645 moles O2

Convert 0.17645 mole of O2 into volume at S.T.P

Mole (n) = volume (dm3) / Molar volume (22.4dm3/mole)
Volume = mole × molar volume
= 0.17645 mole × 22.4dm3/mole
= 3.95248dm3

3.95248dm3 of oxygen gas was produced