P and Q are two elements which form `P_2Q_3` and `PQ_2` molecules. If 0.15g mole of each weighs 15.9g and 9.3g respectively. What are the atomic masses of the elements P and Q.

Explanation

Let the atomic mass of P be 'a' and that of Q be 'b'
Molecular mass of `P_2Q_3` = 2a+ 3b = 15.9/0.15 = 106
Molecular mass of `PQ_2` = a+2b = 9.3/0.15 = 62
Hence a = 26, b = 18
Atomic mass of P is 26 and that of Q is 18.