2.76 g of silver carbonate on being strongly heated yields a residue weighing

The total number of electrons is one molecule of carbon dioxide is

A gaseous mixture contains oxygen and nitrogen in the ratio of 1 : 4 by weight. Therefore the ratio of their no of molecules is

(a). 5.5 g of a mixture FeSO₄.7H₂O and Fe₂(SO₄)₃.9H₂O requires 5.4 ml of 0.1 N KMnO₄ solution for complete oxidation. Calculate the number of gram mole of hydrated ferric sulphate in the mixture.

(b). The vapour density (hydrogen = 1) of a mixture consisting of NO₂ and N₂O₄ is 38.3 at 26.7^oC. Calculate the number of moles of NO₂ in 100 g of the mixure.