Question

Mix well 72g of pure $Mo{O}_5$ with 200 ml of water, and add 60 ml of conc. ammonium hydroxide. When a solution is complete, filter and pour filtrate, very slowly and with rapid stirring, into a mixture of 270 ml of conc. $HN{O}_3$ and 400 ml of water. Allow to stand overnight, filter and dilute to 1 liter. We get the reagent:

• A. ammonium pentaoxide molybdate
• B. ammonium hexaoxide molybdate
• C. ammonium trioxide molybdate
• D. ammonium molybdate

Answer 1

The correct option is D ammonium molybdate

$7Mo{O}_5+6N{H}_{4}OH+conc.HN{O}_3⟶(N{H}_4{)}_{6}M{o}_7{O}_{24}+N{O}_2\uparrow +H_{2}O$

We get the reagent ammonium molybdate.