Advertisements
Advertisements
प्रश्न
When heated, potassium permanganate decomposes according to the following equation:
\[\ce{2KMnO4 -> \underset{solid residue}{K2MnO4 + MnO2} + O2}\]
Some potassium permanganate was heated in test tube. After collecting one litre of oxygen at room temperature, 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.
Advertisements
उत्तर
\[\ce{2KMnO4 -> K2MnO4 + MnO2 + O2}\]
Loss in mass = 1.32 g = 1 lit of oxygen
Vapour density of gas = `"Wt. of certain volume of gas"/"Wt. of same volume of H"_2`
= `1.32/0.0825`
= 16 g
Molecular weight = 2 × Vapour density
= 2 ×16
= 32 g
∴ Relative molecular mass of oxygen is 32 g.
APPEARS IN
संबंधित प्रश्न
Calculate the relative molecular mass of Chloroform.
(use K = 39, Cl = 35.5, O = 16, C = 12, H = 1, Na = 23, N = 14, S= 32)
Calculate the relative molecular mass of Ammonium sulphate.
(use K = 39, Cl = 35.5, O = 16, C = 12, H = 1, Na = 23, N = 14, S= 32)
An organic compound has the following percentage composition: C = 12.76%, H = 2.13%, Br = 85.11%. The vapour density of the compound is 94. Find out its molecular formula.
Concentrated nitric acid oxidises phosphorus to phosphoric acid according to the following equation:
\[\ce{P + 5HNO3 -> H3PO4 + H2O + 5NO2}\]
- What mass of phosphoric acid can be prepared from 6.2 g of phosphorus?
- What mass of nitric acid will be consumed at the same time?
- What will be the volume of steam at the same time measured at 760 mm Hg pressure and 373°C?
(H = 1; N = 14; O = 16; P = 31∴ )
Give one word or phrase for the following:
The ratio of the mass of a certain volume of gas to the mass of an equal volume of hydrogen under the same conditions of temperature and pressure.
Complete the following calculations. Show working for complete credit :
If the empirical formula of a compound is CH and it has a vapour density of 13, find the molecular formula of the compound.
Find the weight of 0.5 mole of O2.
The mass of 5.6 litres of a certain gas at S.T.P. is 12 g. What is the relative molecular mass or molar mass of the gas?
Calculate the volume occupied at S.T.P. by 2 moles of SO2.
67.2 litres of hydrogen combines with 44.8 litres of nitrogen to form ammonia under specific conditions as:
\[\ce{N2_{(g)} + 3H2_{(g)} -> 2NH3_{(g)}}\]
Calculate the volume of ammonia produced. What is the other substance, if any, that remains in the resultant mixture?
