Question

A compound is made up of two elements A and B has A = 70% B = 30%. Their relative number of moles in the compound are 1.25 and 1.88 respectively
a) Calculate masses of A and B.
b) Molecular formula of the compound if its molecular mass is around 160

Answer 1

Let the total mass of the compound be 100g

Then Element A in the compound will be 70g

And Element B in the compound will be 30 g

a) Mass of A

Applying formula;

No of moles of A= Weight given of A /molecular mass

1.25= 70/molecular mass

molecular mass= 70/1.25

= 56g

Mass of B

No of moles of B = Weight given of B/ Molecular mass

1.88= 30/molecular mass

molecular mass=30/1.88

=15.95g