Question

When 24g of magnesium combines with oxygen forming 40g of oxide. The equivalent weight of magnesium is:

Answer 1

Hint: Equivalent weight is defined as the mass of one equivalent which is the mass of a given substance which will combine with or displace a particular fixed quantity of another substance. The equivalent weight of an element can be defined in the terms of the mass which combines with or displaces 1.008 gram of hydrogen or 8.0 grams of oxygen or 35.5 grams of chlorine. So in this question as we are given oxide we will solve it by using the mass of magnesium required to react with 8g oxygen.

Complete step by step answer:
It is given that,
Mass of magnesium = 24g
Mass of magnesium oxide is 40 g
Then by law of conservation of mass,
Mass of oxygen combined will be = 40 – 24 = 16g
The equivalent weight of magnesium can be defined in the terms of the mass which combines with or displaces 8.0 grams of oxygen. So we will calculate the mass of magnesium required to react with 8g oxygen.
16g of oxygen combines with 24g of magnesium so
For 8g oxygen, required mass of magnesium will be given by unity method as
\[=\dfrac{24}{16}\times 8\]= 12g


Note:
Magnesium oxide also known as magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium. It has an empirical formula of \[MgO\] and consists of a lattice of Magnesium ions and oxide ions held together by ionic bonding.