A sample containing 0.4775g of $(NH_4)_2C_2O_4$ and inert materials was dissolved in water and made strongly alkaline with KOH ,which converted $NH_4^+$ to $NH_3$.The liberated ammonia was distilled into exactly 50.0ml of 0.05035M $H_2SO_4$.The excess $H_2SO_4$ was back titrated with 11.3ml of 0.1214M $NaOH$.Calculate percent of N,percent of $(NH_4)_2C_2O_4$.(Mol.wt of $(NH_4)_2C_2O_4=124.10$ and at .wt.of N=14.0078)