a sample of Mg was burnt in air to give a mixture of Mgo and Mg3N2 . The ash was dissolved in 60 Meq of Hcl and the resulting solution was back titrated with NaOH . 12Meq of NaOH were required to reach the end point. An excess of NaOH was then added and the solution distilled . the ammonia released was then trapped in10 Meq of second acid solution. Back titration of this solution required 6 Meq of the base . Calculate the % of Mg burnt to the nitrate.