A salt is formed due to the reaction between an oxy acid containing chlorine and a base containing a monovalent metal of atomic mass x. The number of oxygen atoms in one molecule of the acid is more than the corresponding 'ic' acid. Calculate the molecular mass of the salt.

An oxy-acid containing chlorine with the name ending with 'ic' acid is chloric acid, HClO3. The number of oxygen atoms in one molecule of the acid is more than the corresponding 'ic' acid. Hence, our oxyacid is perchloric acid HClO4. Let our base be MOH where M is a monovalent metal of atomic mass x. The acid-base reaction is : HClO4 + MOH → MClO4 + H2O The atomic masses of metal, Cl and O are x g/mol, 35.5 g/mol and 16 g/mol respectively. The molecular mass of the salt MClO4 is x + 35.5 + 4(16) = 99.5 + x Hence, the correct answer is option B.