Question

The atomic mass of nitrogen is 14.01, hydrogen is 1.01, sulfur is 32.07, and oxygen is 16.00. What is the molar mass of ammonium sulphate [(NH4)2SO4]?
A.
63.09 g
B.
84.17 g
C.
114.12 g
D.
118.16 g
E.
132.17 g

Answer 1

To calculate the molar mass of ammonium sulfate \((NH_4)_2SO_4\), we need to add up the atomic masses of all the atoms in the formula.

1. **Nitrogen (N)**: There are 2 nitrogen atoms in \((NH_4)_2SO_4\).
- Atomic mass of N = 14.01 g/mol
- Total for nitrogen: \(2 \times 14.01 = 28.02 \, \text{g/mol}\)

2. **Hydrogen (H)**: There are 8 hydrogen atoms in \((NH_4)_2SO_4\) (4 from each ammonium ion).
- Atomic mass of H = 1.01 g/mol
- Total for hydrogen: \(8 \times 1.01 = 8.08 \, \text{g/mol}\)

3. **Sulfur (S)**: There is 1 sulfur atom in \((NH_4)_2SO_4\).
- Atomic mass of S = 32.07 g/mol
- Total for sulfur: \(1 \times 32.07 = 32.07 \, \text{g/mol}\)

4. **Oxygen (O)**: There are 4 oxygen atoms in \((NH_4)_2SO_4\).
- Atomic mass of O = 16.00 g/mol
- Total for oxygen: \(4 \times 16.00 = 64.00 \, \text{g/mol}\)

Now, we sum all these contributions to get the total molar mass:

\[
\text{Total molar mass} = 28.02 \, \text{g/mol (N)} + 8.08 \, \text{g/mol (H)} + 32.07 \, \text{g/mol (S)} + 64.00 \, \text{g/mol (O)}
\]
\[
= 28.02 + 8.08 + 32.07 + 64.00 = 132.17 \, \text{g/mol}
\]

Therefore, the molar mass of ammonium sulfate \((NH_4)_2SO_4\) is **E. 132.17 g**.