P and Q are two elements which form P2Q3 and PQ2. If 0.15 mole of P2Q3 weighs 15.9 g and 0.15 mole of PQ2 weighs 9.3 g, then what are atomic weights of P and Q

Asked by Anil | 12th May, 2017, 09:30: PM

Expert Answer:

Lets assume the atomic masses of P and Q are x and y respectively.

 

Mw of P2Q3 = 2 x + 3 y 

MW of PQ2 = x + 2 y

 

we know moles = weight/ mw

 

so, 2x + 3y = 15.9/ 0.15 

x + 2y = 9.3/ 0.15

 

Solving these equations, you will get x= 26, y =18 

Answered by Vaibhav Chavan | 13th May, 2017, 05:47: PM