On passing 10.0 L of a gaseous mixture of nitrogen dioxide and N_2 at STP through a NaOH solution, a mixture of sodium nitrite and sodium nitrate in formed. A mass of 6.32 g of KMnO_4 is required to oxidise the above sodium nitrite in a H_2SO_4 medium. Determine the mass percentage of the gaseous mixture (N_2 does not react with NaOH.)

On passing 10.0 L of a gaseous mixture of nitrogen dioxide and N_2 at

1.	On passing 10.0 L of a gaseous mixture of nitrogen dioxide and N_2 at STP through a NaOH solution, a mixture of sodium nitrite and sodium nitrate in formed. A mass of 6.32 g of KMnO_4 is required to oxidise the above sodium nitrite in a H_2SO_4 medium. Determine the mass percentage of the gaseous mixture (N_2 does not react with NaOH.)
Answer» Solution :`N_2` does not REACT with NaOH. So only `NO_2` reacts with NaOH. `2NO_2+2NaOHtoNaNO_3+NaNO_2+H_2O` `5NaNO_2+2KMnO_4+3H_2SO_4toK_2SO_4+2MnSO_4+5NaNO_3+3H_2O` `therefore2 MOL KMnO_4-=5 mol NaNO_2` ALSO: `2 mol NO_2-=1 mol NaNO_2` `implies0.1 mol NaNO_2-=0.2mol NO_2` `-=0.2xx22.4L at STP` `-=4.48 LIT. NO_2` or `(10-4.48)LN_2=5.52L of N_2-=0.246 " mol of "N_2` " mol of "`NO_2=0.2-=0.2xx46=9.2g` `% of NO_2=57.18%` `" mol of "N_2=0.246=0.246xx28=6.28g` `% of N_2=42.82%`