Advertisements
Advertisements
प्रश्न
When heated, potassium permanganate decomposes according to the following equation :
\[\ce{2KMnO4 -> \underset{\text{solid residue}}{K2MnO4 + MnO2} + O2}\]
(a) Some potassium permanganate was heated in the 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.
(b) Given that the molecular mass of potassium permanganate is 158. What volume of oxygen (measured at room temperature) would be obtained by the complete decomposition of 15.8 g of potassium permanganate? (Molar volume at room temperature is 24 litres)
Advertisements
उत्तर
(a) 1 litre of oxygen has mass = 1.32 g
So, 24 litres (molar vol. at room temp.) will have mass = 1.32 x 24
= 31.6 or 32 g
(b) 2KMnO4 → K2MnO4 + MnO2 + O2
316 g of KMnO4 gives oxygen = 24 litres
So, 15.8 g of KMnO4 will give = 24 × 316/15.8 = 1.2 litres
संबंधित प्रश्न
Calculate the relative molecular mass of Potassium chlorate.
(use K = 39, Cl = 35.5, O = 16, C = 12, H = 1, Na = 23, N = 14, S=32)
Calculate the percentage of boron (B) in borax (Na2B4O7.10H2O). [H = 1, B = 11, O = 16, Na = 23],
answer correct to 1 decimal place.
If a crop of wheat removes 20 Kg of nitrogen per hectare of soil, what mass of the fertilizer calcium nitrate,Ca(NO3)2 would be required to replace nitrogen in 10 hectare field? (N = 14, O = 16, Ca = 40)
When heated, potassium permanganate decomposes according to the following equation:
\[\ce{2KMnO4 -> \underset{solid residue}{K2MnO4 + MnO2} + O2}\]
Given that the molecular mass of potassium permanganate is 158 g, what volume of oxygen (measured at room temperature) would be obtained by the complete decomposition of 15.8 g of potassium permanganate? (Molar volume at room temperature is 24 litres). [K = 39, Mn = 55, O = 16]
Calculate the volume of oxygen required for the complete combustion of 8.8 g of propane (C3H5).
(Atomic mass: C = 14, O = 16, H = 1, Molar Volume = 22.4 dm3 at STP.)
Give one word or phrase for the following:
Formation of ions from molecules.
Give two tests of the following:
Oxygen
Calculate the relative molecular mass of:
CHCl3
Find the weight of 0.2 mole of H2 gas.
A gas cylinder filled with hydrogen holds 5 g of the gas. The same cylinder holds 85 g of gas X under the same temperature and pressure. Calculate the vapour density of gas X.
