Mg can reduce NO_(3)^(-)" to " NH_(3) in basic medium. NO_(3)^(-) + Mg (s) + H_(2)O to Mg (OH)_(2)(s) + OH^(-) (aq) + NH_(3)(g) A 25.0 ml sample of NO_(3)^(-) solution was treated with Mg. The NH_(3)(g) waspassed into 50 ml of 0.15 N HCl . The excess of HCl required 32.10 ml of 0.10 g NaOH for neutralization . What was the molarity of NO_(3)^(-) ions in the original sample ?

Mg can reduce NO_(3)^(-)" to " NH_(3) in basic medium. NO_(3)^(-) + M

1.	Mg can reduce NO_(3)^(-)" to " NH_(3) in basic medium. NO_(3)^(-) + Mg (s) + H_(2)O to Mg (OH)_(2)(s) + OH^(-) (aq) + NH_(3)(g) A 25.0 ml sample of NO_(3)^(-) solution was treated with Mg. The NH_(3)(g) waspassed into 50 ml of 0.15 N HCl . The excess of HCl required 32.10 ml of 0.10 g NaOH for neutralization . What was the molarity of NO_(3)^(-) ions in the original sample ?
Answer» SOLUTION :MEQ . of`NH_(3)` formed = Meq. of HCl used `= 50 xx 0.15 - 32.10 xx 0.10` ` = 4.29` Here, N-factor of `NH_(3)` is 1 (acid - base reaction) For REDOX change, (n- factor = 8) ` :. ` Meq. of `NH_(3)` for n- factor `8 = 8 xx 4.29` ` :. ` Normality of `NO_(3)^(-) = (34.32)/25 = 1.37` Molarity of `NO_(3)^(-) = (1.37)/8 = 0.176`