What is the molar mass of Al_2(SO_4)_3?

• A. 150.03 g/mol
• B. 450.09 g/mol
• C. 342.17 g/mol
• D. 278.03 g/mol

Answer: (C)

Verified step by step guidance

1. Identify the chemical formula given: Al_2(SO_4)_3. This means the compound contains 2 aluminum (Al) atoms, 3 sulfate (SO_4) groups.
2. Determine the atomic masses of each element involved from the periodic table: Aluminum (Al), Sulfur (S), and Oxygen (O).
3. Calculate the total mass contributed by aluminum: multiply the atomic mass of Al by 2 (since there are 2 Al atoms).
4. Calculate the total mass contributed by sulfur: multiply the atomic mass of S by 3 (since there are 3 sulfate groups, each containing 1 S atom).
5. Calculate the total mass contributed by oxygen: multiply the atomic mass of O by 12 (since each sulfate group has 4 O atoms, and there are 3 sulfate groups, total 4 × 3 = 12 O atoms). Then, sum all these contributions to find the molar mass of Al_2(SO_4)_3.