Question

3.4gm of H2O2 decomposes the weight of oxygen liberated is

Answer 1

We first write the equation for the decomposition as follows:

H₂O₂ (aq) -------> 2 H₂O (l) + O₂ (g)

The moles of H₂O₂ decomposing are :

Molar mass of hydrogen peroxide is :

32 + 2 = 3g/mol

moles are :

3.4/34 = 0.1 moles.

The mole ratio of hydrogen peroxide to oxygen is :

2 : 1

The moles of oxygen liberated is thus:

0.1/2 = 0.05 moles

weight of oxygen liberated is thus :

molar mass of oxygen gas = 32

0.05 × 32 = 1.6 grams