KMnO4 decomposes on heating according to the equation-
2KMnO4→K2MnO4+MnO2+O2
On heating KMnO4, 1 litre of oxygen was collected at room temperature and it was found that the test tube had undergone a loss in mass of 1.32 g. If one litre of hydrogen under the same conditions of temperature and pressure has a mass of 0.0825 g. Calculate the relative molecular mass of oxygen.
32 g
Vapour density of oxygen = Weight of 1 litre of gas O2Weight of 1 litre of H2
Weight of 1 litre of oxygen = 1.32 g [since on collecting 1 litre of O2 the loss in mass is 1.32 g]
Vapour density of oxygen = 1.320.0825 = 16
Relative molecular mass of oxygen = 2 × Vapour density = 32 g.