What is the percent composition by mass of nitrogen in (NH4)2CO3 (gram-formula mass = 96.0 g/mol)?

(1) 14.6%
(2) 29.2%
(3) 58.4%
(4) 87.5%

Respuesta :

The percentage composition by mass of nitrogen in [tex]{\left( {{\text{N}}{{\text{H}}_{\text{4}}}} \right)_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] is [tex]\boxed{\left( 2 \right){\text{ 29}}{\text{.2 \% }}}[/tex].

Further explanation:

The most commonly applied concentration terms are as follows:

1. Molality

2. Mole fraction

3. Molarity

4. Parts per million

5. Mass percent

6. Volume percent

7. Percentage composition

The given compound is [tex]{\left( {{\text{N}}{{\text{H}}_{\text{4}}}} \right)_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex]. It contains two atoms of nitrogen, eight atoms of hydrogen, one atom of carbon and three atoms of oxygen.

The mass of nitrogen in [tex]{\left( {{\text{N}}{{\text{H}}_{\text{4}}}} \right)_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] can be calculated as follows:

[tex]{\text{Mass of N}} =\left( {{\text{Number of nitrogen atoms}}} \right)\left( {{\text{Molar mass of nitrogen}}} \right)[/tex]              …… (1)

The number of N atoms in [tex]{\left( {{\text{N}}{{\text{H}}_{\text{4}}}} \right)_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] is 2.

The molar mass of nitrogen is 14.01 g/mol.

Substitute these values in equation (1).

 [tex]\begin{aligned}{\text{Mass of nitrogen}} &= \left( {\text{2}} \right)\left( {{\text{14}}{\text{.01 g/mol}}} \right)\\&= 28.02{\text{ g/mol}}\\\end{aligned}[/tex]

The formula to calculate the percentage composition of N in [tex]{\left( {{\text{N}}{{\text{H}}_{\text{4}}}} \right)_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] is as follows:

[tex]{\text{\%  composition of N}} = \left( {\dfrac{{{\text{Mass of N}}}}{{{\text{Mass of }}{{\left( {{\text{N}}{{\text{H}}_{\text{4}}}} \right)}_{\text{2}}}{\text{C}{{\text{O}}_{\text{3}}}}}} \right){\text{100 \% }}[/tex]                                       …… (2)

The mass of N is 28.02 g/mol.

The mass of [tex]{\left( {{\text{N}}{{\text{H}}_{\text{4}}}} \right)_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] is 96.0 g/mol.

Substitute these values in equation (2).

[tex]\begin{aligned}{\text{\%  composition of N}} &= \left( {\frac{{{\text{28}}{\text{.02 g/mol}}}}{{{\text{96}}{\text{.0 g/mol}}}}} \right){\text{100 \% }}\\&= {\text{29}}{\text{.1875 \% }} \\ &\approx {\text{2}}{\text{.92 \%}}\\\end{aligned}[/tex]  

Therefore the percentage composition by mass of nitrogen in [tex]{\left( {{\text{N}}{{\text{H}}_{\text{4}}}} \right)_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] is 29.2 %.

Learn more:

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Answer details:

Grade: Senior School

Chapter: Concentration terms

Subject: Chemistry

Keywords: (NH4)2CO3, N, nitrogen, mass, 2.92 %, 96.0 g/mol, 28.02 g/mol, nitrogen, hydrogen, carbon, oxygen, mass of N, mass of (NH4)2CO3.

The % composition of nitrogen is 29.166% ~ 29.2%. Thus option 2 is correct.

The percent composition of nitrogen in ammonium carbonate can be calculated as:

% Composition = [tex]\rm \dfrac{mass\;of\;element}{mass\;of\lcompound}\;\times\;100[/tex]

Mass of nitrogen in the compound has been:

Number of Nitrogen atoms = 2

Mass of 1 nitrogen atom = 14 g/mol

Mass of 2 nitrogen atom = 28 g/mol

Mass of compound = 96 g/mol

% Composition of nitrogen = [tex]\rm \dfrac{28}{96}\;\times\;100[/tex]

% Composition of nitrogen = 29.166 %

The % composition of nitrogen is 29.166% ~ 29.2%. Thus option 2 is correct.

For more information about the percent composition, refer to the link:

https://brainly.com/question/17505281