Question
Question: If \(Ksp\) for \(HgS{O_4}\) is \(6.4 \times {10^{ - 5}}\) , then solubility of this substance in mo...
If Ksp for HgSO4 is 6.4×10−5 , then solubility of this substance in mole per m3 is:
Hg=200,S=32,O=16
A. 8×10−3
B. 8×10−6
C. 296
D. 2368
Solution
For a compound like HgSO4 , the ratio of Hg+2:SO4−2 is 1:1 . That is for every mercury ion there is one sulphate ion. This means that the solubility product for the compound is the square of the solubility that is s2 where s is the solubility.
Formula used: Ksp= s2
Where Ksp is the solubility constant and s is the solubility.
Complete step by step answer:
In this question, we have two ions, there is Hg+2and SO4−2 . Therefore, the reaction of dissociation will look like this:
HgSO4⇄Hg+2+SO4−2
now we can consider the concentration of Hg+2to be s and the concentration of SO4−2 to be equal to Hg+2 .
The equilibrium constant can be represented in the following way:
Ksp=[Hg+2][SO4−2]
Concentration of mercury and sulphate ions is represented in the manner shown above.
Ksp=[s][s]
Ksp=[s]2
For this reason, the equilibrium constant which is called a solubility product is the product of both the ions to form s2 . The solubility of a solute can be defined as the amount of a solute that can be dissolved in a given amount of solvent at a particular temperature at a state of equilibrium.
According to the question, we have Ksp to be 6.4×10−5 . This can be used to calculate the s or solubility using the above formula.
6.4×10−5=s2
Ksp=s2
64×10−6=s2
64×10−6=s
8×10−3=s
So, the correct answer is Option A.
Note: It is important to remember the relation between the solubility product and the solubility s . It can vary depending on the number of ions a particular compound can form.
The solubility product Ksp is a constant and does not depend on temperature change. It also does not have a unit.
Solubility is dependent on change in temperature. It has a unit, m3mole .
The more the Ksp is the higher the solubility of the solute in a solution.