Question

Question Objective : Formula Based
10 grams of metal oxide on strong heating gave 1.6 grams of oxygen. The gram equivalent weight of metal is
A) 42g
B) 50g
C) 12g
D) 249
Answer: A​

Answer 1

Answer:

According to Law of conservation of Mass,

Mass of Metal Oxide = Mass of Metal + Mass of Oxide

⇒ 10g = x + 1.6g

⇒ x = 10g - 1.6g

⇒ x = 8.4g

Hence the mass of metal is 8.4g.

The equivalent mass of metal is nothing but the mass of metal combining with 8g of oxygen.

According to the question, 8.4g of metal combines with 1.6g of oxygen. Hence y grams of metal will combine with 16g. Solving it we get:

⇒ 8.4g of M : 1.6g of O :: y g of M : 8g of O

$\implies y = \dfrac{8.4 \times 8}{1.6}\\\\\boxed{\implies y = 42g}$

Since the equivalent weight is expressed in grams, it is called as gram equivalent weight.

Hence Option A is the correct answer.