Question

The correct formula of calcium hydrogen sulfate is:
(a) $\text{Ca}{{\text{H}}_{2}}\text{S}{{\text{O}}_{4}}$
(b) $\text{CaHS}{{\text{O}}_{4}}$
(c) $\text{Ca(HS}{{\text{O}}_{4}}{{)}_{2}}$
(d) $\text{C}{{\text{a}}_{2}}\text{HS}{{\text{O}}_{4}}$
(e) $\text{C}{{\text{a}}_{2}}{{\text{H}}_{2}}\text{S}{{\text{O}}_{4}}$

Answer 1

Hint: The chemical formula of calcium hydrogen sulfate is found by using the concept of the valency of the atom which is the capacity of any substance to gain/lose the electron. Valency of Ca is +2 and that of the $\text{HS}{{\text{O}}_{4}}$is -1. Now, find the chemical formula.

Complete step by step answer:
Calcium hydrogen sulfate is an inorganic compound and it consists of the elements calcium, hydrogen and sulphate and it is formed by the action of the Sulphur dioxide on the calcium hydroxide and results in the formation of calcium hydrogen sulfate.
We can find the formula of calcium hydrogen sulfate by using their valency i.e. on the basis of their tendency to lose or gain the electrons.
Calcium atoms can lose a maximum of 2 electrons from its valence shell to attain the nearest noble gas configuration and thus exhibit +2 oxidation state in most of their compounds and so, there valency is +2. On the other hand, hydrogen sulphate has a tendency to gain one electron and thus exhibits -1 oxidation state in their compounds and so, their valency is -1.
So, the chemical formula of calcium sulfate is:
 Ca HS${{\text{O}}_{4}}$
   2 1
On cross multiplication, 1 with Ca and 2 with Ca, the chemical formula of the calcium sulphate turn out to be: $\text{Ca(HS}{{\text{O}}_{4}}{{)}_{2}}$ or the formula of calcium hydrogen sulfate can also be written as: $\text{Ca}{{\text{H}}_{2}}{{\text{S}}_{2}}{{\text{O}}_{8}}$,

Hence, the option(c) is correct.

Note: Keep in mind the valency of calcium and the hydrogen sulfate and in the hydrogen sulfate we will not consider the valency of individual atoms present in it i.e. the valencies of individual atoms i.e. hydrogen, oxygen and Sulphur would not be considered and the overall valency of hydrogen sulfate is taken in it which is -1.