5 mL of 0.4 N NaOH is mixed with 20 mL of 0.1 N HCl.The pH of the resulting solution will be
7
8
5
6
The pH of the solution obtained by mixing 100 ml of a solution of pH = 3 with 400 mL of a solution of pH = 4 is
7 - log 2.8
4 - log 2.8
5 - log 2.8
3 - log 2.8
The equilibrium constant of the reaction
A (s) + 2B2+ (aq) A2+ (aq) + 2B (s);
E
2 × 102
3 × 102
2 × 105
10
An example for a neutral buffer is
ammonium hydroxide and ammonium chloride
acetic acid and sodium acetate
acetic acid and ammonium hydroxide
citric acid and sodium citrate
For Cr2O + 14 H+ + 6e- → 2Cr3+ + 7H2O; E° = 1.33 V. At [Cr2O] = 4.5 millimole, [Cr3+] = 15 millimole, E is 1.067 V. The pH of the solution is nearly equal to
2
3
5
4
The pH of 10-8 M HCl solution is
8
6.9586
more than 8
slightly more than 7
B.
6.9586
As HCl solution is acidic in nature and the pH of an acidic solution cannot exceed more than 7 .Thus, the answer must be 6.9586.
We can also find this answer through calculations From acid, [H+]=10-8M
But the [H+] ions from water, i.e [H+]= 10-7M cannot be neglected in comparison to 10-8M. The pH can be calculated as follows
From acid, [H+]=10-8M and from water, [H+]= 10-7 M
Total [H+]=10-8M + 10-7 M = 10-8(1+10)
= 11 × 10-8M
pH = -log [H+]
= -log( 11 × 10-8M)
= -[log11 + log 10-8)
=-[1.0414-8] = 6.9586
For the equilibrium,
CaCO3 (s) CaO (s) + CO2 (g) ;
Kp = 1.64 atm at 1000 K
50 g of CaCO3 in a 10 L closed vessel is heated to 1000 K. Percentage of CaCO3 that remains unreacted at equilibrium is (Given, R = 0.082 L atm K-1 mol-1).
40
50
60
20
The acid strength of active methylene group in
I. CH3COCH2COOC2H5
II. CH3COCH2COCH3
III. C2H5OOCCH2COOC2H5
decreases as
I > III > II
I > II > III
II > I > III
III > I > II