Question

How do I calculate the molecular weight of Mg(OH)2?

Answer 1

To calculate the molecular weight of Mg(OH)2, add the atomic weights of all the elements in the compound.

Step-by-step explanation:

The molecular weight of Mg(OH)2 can be calculated by summing the atomic weights of all the elements in the compound. In Mg(OH)2, there is 1 magnesium atom (with a molar mass of 24.305 g/mol), 2 oxygen atoms (with a molar mass of 15.999 g/mol each), and 2 hydrogen atoms (with a molar mass of 1.008 g/mol each).

To calculate the molecular weight, you would add:

24.305 g/mol (Mg) + 15.999 g/mol (O) + 15.999 g/mol (O) + 1.008 g/mol (H) + 1.008 g/mol (H) = 58.32 g/mol

Answer 2

The molecular weight of Mg(OH)2 : 58 g/mol

Further explanation

Given

Mg(OH)2 compound

Required

The molecular weight

Solution

Relative atomic mass (Ar) of element : the average atomic mass of its isotopes

Relative molecular weight (M) : The sum of the relative atomic mass of Ar

M AxBy = (x.Ar A + y. Ar B)

So for Mg(OH)2 :

= Ar Mg + 2 x Ar O + 2 x Ar H

= 24 g/mol + 2 x 16 g/mol + 2 x 1 g/mol

= 24 + 32 + 2

= 58 g/mol