## Chemistry: A Molecular Approach (3rd Edition)

$NH_{3}$ has the highest nitrogen content.
1-$NH_{3}$ To calculate the percentage composition by mass of nitrogen in a compound, we find the total molar mass of nitrogen in a compound which is 14 and divide by the total molar mass of the compound which is 14+3= 17, 14÷17= 0.823 To find percentage, multiply by 100: 14/17 ×100= 82.35% 2-$CO(NH_{2})_{2}$ First, we calculate the total molar mass of nitrogen in a compound: 2x14=28 Then, we divide it by the total molar mass of the compound: 12+16+(2×14)+(4×1)=60 Therefore, 28/60=0.466 Multiply by 100 to get the percentage by composition: 28/60 x 100= 46.67% 3-$(NH_{3})_{2}SO_{4}$ Total molar mass of nitrogen: 2x14=28 Total molar mass of the compound:(2x14)+(8×1)+32.1+(4×16)= 132.1 Divide the molar mass of nitrogen by the molar mass of the compound: 28÷132.1= 0.2119 Multiply by 100 to find the percentage: 28/132.1 ×100= 21.20% $NH_{3}$ has the highest nitrogen content.