Question

an ionic compound of element M and chlorine has the formula MCL3. the molar mass of MCl3 is 118. 5u. what is the molar mass of the oxide of element M?

Answer 1

Molar Mass of MCl₃ = 118.5 u
Atomic Mass of Cl = 35.5 u
We know,
Atomic Mass of M = Molar mass of MCl₃ - Mass of Cl
= 118.5 - (3×35.5) = 12 u
So, Molecular Formula of MCl₃ = M₂O₃     [valency of metal is 3]
∴ Molar Mass of M₂O₃
⇒(2×12) + (3×16)
⇒24+48
⇒72 u

Answer 2

see attachment....hope it will help u