You have been given a solution containing chloroform and toluene, the concentration of chloroform is specified as 40 mole percent , toluene 60 mole percent. what is the mass percentage of chloroform in this solution ?

In 1 mole of mixture
0.4 mole of chloroform (CHCl3), mass =0.4*119.5=47.8g chloroform
0.6 mole toluene C7H8, mass =0.6*92=55.2 g toluene
mass of solution 47.8+55.2=103 g
mass% of chloroform=(47.8/103)*100%=46.4%
mass%of toluene=(55.2/103)*100%=53.59%

(no3)⁻n has oxidation number x,o has oxidation number -2.(x*1 -2*3) charge of the nitrate ion, and we know that charge of the nitrate ion =-1.so,(x*1 -2*3) =-1x-6=-1x=+5answer a. +5.