Q.

The molarity of 1 L orthophosphoric acid (H3PO4) having 70% purity by weight (specific gravity 1.54 g cm-3) is ______ M.
(Molar mass of H3PO4 = 98 g mol-1)                       [2024]


Ans.

(11)

        70% w/w H3PO4 solution means:

        70 g H3PO4 in 100 g solution

       7098 mol H3PO4 in 1001.54 mL solution

         M=nsoluteVsolution(in mL)×1000

        M=70/98100/1.54×1000 M=70×1.54×100098×100 M=11M