4.215 g of a metallic carbonate was heated in a hard glass tube and the CO₂ evolved was found to measure 1336 ml at 27^oC and 700 mm pressure. What is the equivalent weight of metal?

(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.

Account for the following : Limit your answer to two sentences.

"Atomic weights of most of the elements are fractional."

What weight of AgCl will be precipitated when a solution containing 4.77 g of NaCl is added to a solution of 5.77g of AgNO₃?