Question

A metallic fluoride contains 66.78% fluorine. One mole of that compound contains 1.5 times the number of fluorine in one mole of dry fluorine gas. Find out the atomic weight of the metal:

• A. 40 g
• B. 27 g
• C. 31 g
• D. 23 g

Answer 1

The correct option is B 27 g

one mole of dry fluorine has 2 atom of fluorine

compound has 1.5*2 = 3

given that 66.78% of fluorine

then (57*100)/atomic weight of compound = 66.78

atomic weight of compound = 84

atomic weight of metal 84-57= 27