Question

The total number of atoms present in 1 mole of potash alum, in terms of Avogadro number ${N_A}$, is:
[Potash Alum = ${K_2}S{O_4}.A{l_2}{(S{O_4})_3}.24{H_2}O$
A. $3{N_A}$
B. $5{N_A}$
C. $8{N_A}$
D. $32{N_A}$

Answer 1

Hint: This question is asked from the basic concept of chemistry mole concept. We need to know that there are Avogadro numbers of atoms in one mole of a substance.

Complete step by step answer:
We know that the molecular formula of potash alum is ${K_2}S{O_4}.A{l_2}{(S{O_4})_3}.24{H_2}O$. In this potash alum, there are two moles of potassium ions, one mole of sulphate ions, two moles of aluminium ions, three moles of sulphate ions and twenty four moles of water molecules. There are a total of 32 moles of compounds together to form potash alum. Therefore, the number of atoms present in potash alum is 32 Avogadro number of atoms which is equal to $32{N_A}$.
So the correct answer is “D”:

Additional Information: Potash alum is a double salt of potassium and aluminium. Potash alum is mainly used in the purification of water, tanning of leather, dyeing, fireproof textiles, and as baking powder. It also has cosmetic uses as a deodorant, as an aftershave treatment and as a styptic for minor bleeding from shaving.

Note: You should notice that the number of moles of compounds in the questions and the Avogadro number of that much moles of atoms or molecules will present in that substance. This is the simple way to solve this type of mole concept problem.