The standard emf of a cell, involving one electron change is found to be 0.591 V at 25°C. The equilibrium constant of the reaction is (F = 96500 C mol-1)
1.0 × 101
1.0 × 105
1.0 × 1010
1.0 × 1030
The pH of 10-8 M NaOH aqueous solution at 25°C, is
7.02
7.0
6.89
6.0
A.
7.02
[OH-] of NaOH = 10-8M
Since, the concentration of OH- obtained from NaOH is very low, the concentration of OH- water cannot be neglected. Thus,
Total [OH-] = [OH-]NaOH + [OH-]
= 10-8 + 10-7
= 10-7 (1.1) = 1.1 × 10-7
pOH = -log[OH-]
= -log (1.1 × 10-7 ) = 6.96
pH = 14-6.69 = 7.04
At a certain temperature, the solubility of the salt, MmAn in water is s mol/L. The solubility product of the salt is
MmAn
(m + n)sm + n
mmnnsm + n
mmAns
The pKa value of (I) 2 - bromo propanoic acid, (II) 2-fluoro propanoic acid, (III) 3 - fluoro propanoic acid, (IV) 3- bromo propanoic acid decreases as
I > III > IV > II
II > IV > III > I
I > IV > III > II
IV > I > III > II