pKa increases in benzoic acid when substituent "x" is bonded at para-position, then "x" is
-COOH
-NO2
-CN
-OCH3
Assertion : Aqueous solution of CoCl2 is pink in colour. It turns blue in presence of conc. HCl.
Reason : It is due to the formation of [CoCl4]2-.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion 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.
A.
If both assertion and reason are true and reason is the correct explanation of assertion.
According to Le Chatelier's principle, on adding conc. HCl, the equilibrium shifts in forward direction giving blue colour. And when this blue colour is diluted, equilibrium shifts in backward direction leading to pink colour.
The concentration of Ag+ ion in a given saturated solution of AgCl at 25°C is 1.06 x 10-5 g ion L-1 .Thus , the solubility product of AgCl is :
0.453 x 10-10
0.530 x 10-10
1.12 x 10-10
2.12 x 10-10
Solution of 0.l N NH4OH and 0.1 N NH4Cl has pH 9.25. Then , pKb of NH4OH is :
9.75
4.75
3.75
8.25