The molar mass of the metal oxide M2O is 231.74 g/mol. What is the molar mass of the chloride of this metal?

The molar mass of the M2O = 2 (molar mass of M) + molar mass of oxygen

Molar mass of oxygen = 16

Therefore:

231.74 = 2 (molar mass of M) + 16

215.74 = 2*molar mass of M

molar mass of M = 107.87 grams

Now, from the given formula, we can notice that the metal M is monovalnet and we know that chlorine is monovalent as well.

Therefore, the compound formed will be: MCl

molar mass of chlorine = 35.5 grams

Therefore,

molar mass of MCl = 107.87 + 35.5 = 143.37 grams