Question

What is the molecular mass of \( \text{K}_2\text{SO}_4 \)?

• A. \( 174 \, \text{g/mol} \)
• B. \( 132 \, \text{g/mol} \)
• C. \( 144 \, \text{g/mol} \)
• D. \( 94 \, \text{g/mol} \)

Hint:

Remember: To calculate the molecular mass, sum the atomic masses of each element, considering the number of atoms of each element.

Answer 1

The Correct Option is A

Step 1: Determine the molar mass of \( \text{K}_2\text{SO}_4 \)
Sum the atomic masses of each constituent element to find the molar mass:
- Potassium (K): 39 g/mol,
- Sulfur (S): 32 g/mol,
- Oxygen (O): 16 g/mol.
Step 2: Sum the atomic masses
The molecular formula \( \text{K}_2\text{SO}_4 \) indicates the presence of:
- 2 potassium atoms,
- 1 sulfur atom,
- 4 oxygen atoms.
The calculation for the molecular mass is:\[\text{Molecular mass of K}_2\text{SO}_4 = 2 \times 39 + 1 \times 32 + 4 \times 16\]\[= 78 + 32 + 64 = 174 \, \text{g/mol}\]Answer: The molecular mass of \( \text{K}_2\text{SO}_4 \) is \( 174 \, \text{g/mol} \). The correct answer is option (1).