Final answer:
The formula weight of magnesium nitrate, Mg(NO₃)₂, is 148.322 g/mol.
Step-by-step explanation:
The formula weight of magnesium nitrate, Mg(NO₃)₂, can be determined by calculating the molar mass of each element in the compound and then summing them up.
For Mg(NO₃)₂, the molar mass of magnesium (Mg) is 24.305 g/mol, the molar mass of nitrogen (N) is 14.007 g/mol, and the molar mass of oxygen (O) is 15.999 g/mol.
Multiplying the respective molar masses by the number of atoms in the compound and summing them up gives:
Molar mass of Mg(NO₃)₂ = 24.305 g/mol + 2 * (14.007 g/mol * 2 + 15.999 g/mol * 6) = 148.322 g/mol.