Assertion : Mixture of CH3COOH and CH3COONH4 is an example of acidic buffer.
Reason: Acidic buffer contains equimolar mixture of weak acid and its salt with weak base.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both aaertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Which one of the following aqueous solutions of salts has the lowest pH value ?
CH3COONa
NaCl
NH4OOCCH3
NH4Cl
If the solubility of PbCl2 at 25°C is 6.3 x 10-2 mol/L , its solubility product is :
1 x 10-6
1 x 10-3
1.1 x 10-6
1.1 x 10-5
B.
1 x 10-3
PbCl2 completely ionised in the solution as
PbCl2 Pb2+ + 2Cl-
i.e , 1 mole of PbCl2 in the solution gives 1 mole of Pb2+ ion and 2 moles of Cl- ions .
Now , as the solubility of PbCl2
= 6.3 x 10-2 mol/L
[Pb2+] = 6.3 x 10-2 mol/L
and [Cl-] = 2 X 6.3 X 10-2 mol/L
= 12.6 x 10-2 mol/L
Ksp for PbCl2 = [Pb2+][Cl-]2
= (6.3 x 10-2) x (12.6 x 10-2)2
= 1 x 10-3