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

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?