What is the molar mass of Mg(NO3)2?

• A. 124.3 g/mol
• B. 85.0 g/mol
• C. 148.3 g/mol
• D. 62.0 g/mol

Answer: (C)

Verified step by step guidance

1. Identify the chemical formula of the compound: Mg(NO3)2, which consists of 1 magnesium (Mg) atom, 2 nitrogen (N) atoms, and 6 oxygen (O) atoms (since each nitrate ion NO3 contains 3 oxygen atoms and there are 2 nitrate ions).
2. Find the atomic masses of each element from the periodic table: Magnesium (Mg) ≈ 24.3 g/mol, Nitrogen (N) ≈ 14.0 g/mol, Oxygen (O) ≈ 16.0 g/mol.
3. Calculate the total mass contributed by each element by multiplying the atomic mass by the number of atoms: For Mg: \$1 \times 24.3\(, for N: \)2 \times 14.0\(, and for O: \)6 \times 16.0$.
4. Sum all the contributions to find the molar mass of Mg(NO3)2 using the formula: \(\text{Molar mass} = (1 \times 24.3) + (2 \times 14.0) + (6 \times 16.0)\).
5. Add the values from the previous step to get the total molar mass in g/mol, which corresponds to the molar mass of Mg(NO3)2.