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%

The chemical formula is : (NH4) 2CO3

First you need to get the Molar Mass (MM) of the compound.

Here is the solution:

Mol Mass = 'N' 28 + 'H' 8 + 'C' 12 + 'O' 48

Mol Mass = 96 g/mol.

To get the percentage of each elements, you need to divide the molar mass

of the element by the molar mass of the compound and multiply by 100 or

(MM of element / MM of compound x 100).

Here is the solution:

% of N = 28 / 96 = 0.2917 x 100% = 29.17%.

% of H = 8 / 96 = 0.0833 x 100% = 8.33%.

% of C = 12 / 96 = 0.125 x 100% = 12.5%.

% of O = 48 / 96 = 0.5 x 100% = 50%.

(Total = 100%).

From the solution, the answer to your question is that there is 29.2% of

Nitrogen (N) in the compound (NH4) 2CO3.