Question

Assertion: $LiCl{{O}_{4}}$ is more soluble in water than $NaCl{{O}_{4}}$
Reason: $L{{i}^{+}}$ shows more hydration.
A) Both assertion and reason are correct and reason is the correct explanation for assertion.
B) Both assertion and reason are correct but reason is not the correct explanation for assertion.
C) Assertion is correct but reason is incorrect.
D) Both assertion and reason are incorrect.

Answer 1

Hint: the answer here is based upon the general concept of inorganic chemistry which includes the concept of solubility that is based on the size of the cation and which is further dependent on the hydration energy based on the size.

Complete Solution :
In the lower classes, we have studied various parameters that affect the chemical compounds such as solubility, miscibility, melting points, boiling points and many more.

 - Let us now see if the above given assertion and reason is true or not.
$LiCl{{O}_{4}}$ is having the cation as the lithium ion that is $L{{i}^{+}}$ ion.
- Hydration energy is the amount of energy that is released when one mole of the ions undergo hydration.
Since, the hydration energy is also dependent on the size of the cation, we shall see the variation of size in these cations.
In the $LiCl{{O}_{4}}$ molecules and $NaCl{{O}_{4}}$, lithium cation has smaller size when compared to the sodium ion because lithium has lower atomic number that is 3 and sodium has more electrons with atomic number 11.
- Now, if the size of the ion increases the hydration energy decreases and vice versa.
Thus, hydration energy is inversely proportional to the size of the ion.
Thus, $LiCl{{O}_{4}}$ is more soluble in water than $NaCl{{O}_{4}}$
Therefore, the assertion and reason are correct and also the reason is the correct explanation for assertion.
So, the correct answer is “Option A”.

Note: Note that hydration and hydrogenation are the different terms with different meanings. Hydration is the addition of water molecules to the organic compound whereas hydrogenation is the addition of hydrogen atoms to the organic compound.