Which of the following compounds has a molar mass of 174.3 g/mol?

• A. KClO_3
• B. Ba(NO_3)_2
• C. Na_2SO_4
• D. CaCO_3

Answer: (B)

Verified step by step guidance

1. Identify the molecular formula of each compound given: KClO_3, Ba(NO_3)_2, Na_2SO_4, and CaCO_3.
2. Look up the atomic masses of each element involved (approximate values: K = 39.1, Cl = 35.5, O = 16.0, Ba = 137.3, N = 14.0, Na = 23.0, S = 32.1, Ca = 40.1, C = 12.0).
3. Calculate the molar mass of each compound by multiplying the atomic mass of each element by the number of atoms of that element in the formula, then summing all contributions. For example, for Ba(NO_3)_2, calculate: \(\text{Ba} + 2 \times (\text{N} + 3 \times \text{O})\).
4. Compare the calculated molar masses of all compounds to the target molar mass of 174.3 g/mol.
5. Identify which compound's molar mass matches 174.3 g/mol, confirming the correct answer.