What is the [OH-] in the final solution prepared by mixing 20.0 mL of 0.050 M HCI with 30.0 mL of 0.10 M Ba(OH)2 ?
0.10 M
0.40 M
0.0050 M
0.12 M
Which of the following statements about pH and H+ ion concentration is correct ?
Addition of one drop of concentrated HCI in NH4OH solution decreases pH of the solution
A solution of the mixture of one equivalent of each of CH3COOH and NaOH has a pH of 7
pH of pure neutral water is not zero
A cold and conc H2SO4 has lower H+ ion concentration than a dilute solution of H2SO4
The conjugate acid of is
N2H4
NH2OH
NH3
The concentration of [H+ ] and concentration of [OH-] of a 0.1 M aqueous solution of 2% ionised weak monobasic acid is
[ionic product of water = 1× 10-14 ]
0.02 × 10-3 M and 5 × 1011 M
1 × 10-3 M and 3 × 1011 M
2 × 10-3 M and 5 × 1012 M
3 × 10-2 M and 4 × 10-13 M
A physician wishes to prepare a buffer solution at pH = 3.58 that efficiently resist changes in pH yet contains only small concentration of the buffering agents. Which one of the following weak acid together with its sodium salt would be best to use ?
m-chlorobenzoic acid (pKa =3.98)
p-chlorocinnamic acid (pKa = 4.41)
2, 5 - dihydroxy benzoic acid (pKa = 2.97)
Acetoacetic acid (pKa = 3.58)
The compound whose aqueous solution has the highest pH is
NaCI
NaHCO3
Na2CO3
NH4CI
A weak acid, HA, has a Ka of 1.00 × 10-5 . If 0.100 mole of this acid is dissolved in one litre of water, the percentage of acid dissociated at equilibrium is closest to
99.0%
1.00 %
99.9 %
0.100 %
The ionisation constant of ammonium hydroxide is 1.77 × 10-5 at 298 K. Hydrolysis constant of ammonium chloride is
5.65 × 10-10
6.50 × 10-12
5.65 × 10-13
5.65 × 10-12
The strongest conjugate base is
CI-
CH3COO-
Solution of 0.1 NH4OH and 0.1 N NH4CI has pH 9.25, then find out pKb of NH4OH
9.25
4.75
3.75
8.25