AIIMS 2016 Chemistry Question Paper for free online practice with solutions

Question : 22 of 60

Marks: +1, -0

Two elements A and B form compounds of formula AB2 and AB4. When dissolved in 20.0 g of benzene 1.0 g of AB2 lowers f. pt. by 2.3℃ whereas 1.0g of AB4 lowers f. pt. by 1.3℃. The Kf for benzene is 5.1. The atomic masses of A and B are