Final answer:
The formula weight of magnesium hydroxide, Mg(OH)2, is 58.33 amu, calculated by summing the atomic masses of magnesium, oxygen, and hydrogen.
Step-by-step explanation:
The formula weight of magnesium hydroxide, Mg(OH)2, can be calculated by summing the atomic masses of magnesium (Mg), oxygen (O), and hydrogen (H). Each magnesium atom has an atomic mass of about 24.31 amu. Each oxygen atom has an atomic mass of about 16.00 amu, and each hydrogen atom has an atomic mass of about 1.01 amu. Since magnesium hydroxide has one magnesium atom, two oxygen atoms, and two hydrogen atoms, its formula weight is calculated as follows:
Mg: 1 x 24.31 = 24.31 amu
O: 2 x 16.00 = 32.00 amu
H: 2 x 1.01 = 2.02 amu
Adding these together gives us a formula weight of 58.33 amu for magnesium hydroxide.