Question

Consider separate 100.0-g samples of each of the following: nh3, n2o, hcn, n2h4, and hno3. which of the samples has the greatest mass of nitrogen?

Answer 1

To find out which sample has the greatest mass of nitrogen, we must find of the nitrogen concentration of each molecule first.

Concentration of N = Molar mass of N/molecular weight
So,
Conc. of N in NH3 = 14/(14+3*1) = 82.4%
Conc. of N in N2O = (14*2)/(14*2+16) = 63.6%
Conc. of N in HCN = 14/(1+12+14) = 51.9%
Conc. of N in N2H4 = (14*2)/(14*2+4*1) = 87.5%
Conc. of N in HNO3 = 14/(1+14+16*3) = 22.2%

So in 100 g sample of each molecule, the mass of N is 82.4 g in NH3, 63.6 g in N2O, 51.9 g in HCN, 87.5 g in N2H4, 22.2 g in HNO3, respectively.

Therefore, N2H4 has the greatest mass of nitrogen.
 

Answer 2

The sample of N₂H₄ has the greatest mass of nitrogen. 87.42 g of nitrogen are in the 100.0 g sample of N₂H₄.

FURTHER EXPLANATION

Mass percent is the ratio of an element's mass to the mass of the compound. It is mathematically expressed as:

$mass \ \% \ of \ A \ = \frac{mol A \times mass \ A}{mass \ compound} \times 100$

To determine which has the greatest mass of nitrogen, solve for the mass percent of nitrogen in each compound.

• NH₃

$mass \ \% \ of \ N \ = \frac{1 \times 14.007 \ g}{14.007 \ g \ + \ 3(1.008 \ g)} \times 100\\\boxed {mass \ \% \ of \ N \ = 82.24\%}$

• N₂O

$mass \ \% \ of \ N \ = \frac{2 \times 14.007 \ g}{2(14.007) \ g \ + \ 15.999 \ g} \times 100\\\boxed {mass \ \% \ of \ N \ = 63.65\%}$

• HCN

$mass \ \% \ of \ N \ = \frac{ 14.007 \ g}{14.007 \ g \ + \ 12.011 \ g \ + 1.008 \ g} \times 100\\\boxed {mass \ \% \ of \ N \ = 51.83\%}$

• N₂H₄

$mass \ \% \ of \ N \ = \frac{2 \times 14.007 \ g}{2(14.007) \ g \ + \ 4(1.008) \ g} \times 100\\\boxed {mass \ \% \ of \ N \ = 87.42\%}$

• HNO₃

$mass \ \% \ of \ N \ = \frac{14.007 \ g}{ 1.008 \ g \ + 14.007 \ g \ + \ 3(15.999) \ g} \times 100\\\boxed {mass \ \% \ of \ N \ =22.23\%}$

In a 100.0 grams sample, the mass of N will be:

• 82.24 g in 100 g of NH₃
• 63.65 g in 100 g of N₂O
• 51.83 g in 100 g of HCN
• 87.42 g in 100 g of N₂H₄
• 22.23 g in 100 g of HNO₃

Therefore, the sample with the greatest mass of nitrogen is N₂H₄.

LEARN MORE

1. Learn more about Empirical Formula https://brainly.com/question/8516072
2. Learn more about Ways of Expressing Concentration https://brainly.com/question/12936072

Keywords: mass percent, nitrogen