Final answer:
The molar mass of Al2(SO4)3 is calculated by adding the individual molar masses of its constituent atoms, yielding the correct answer of c. 342.17 g/mol.
Step-by-step explanation:
The molar mass of Al2(SO4)3 is the sum of the individual molar masses of aluminum (Al), sulfur (S), and oxygen (O). The molar mass for aluminum is 26.98 g/mol, for sulfur is 32.06 g/mol, and for oxygen is 16.00 g/mol. The molecule consists of 2 aluminum atoms, 3 sulfur atoms, and 12 oxygen atoms. Therefore, the calculation for the molar mass of Al2(SO4)3 is as follows:
(2 × 26.98 g/mol) + (3 × 32.06 g/mol) + (12 × 16.00 g/mol) = 342.14 g/mol
Therefore, the correct answer is c. 342.17 g/mol, which aligns with the given formula mass of 342.14 amu.