Chemistry - Ionic Equilibrium in Aqueous Solution
Exam Duration: 45 Mins Total Questions : 30
Which one of the following solutions is basic?
- (a)
HOCI
- (b)
NaHSO4
- (c)
NH4NO3
- (d)
NaOCI
Which one of the following is a Lewis base?
- (a)
BF3
- (b)
AICI3
- (c)
Ag+
- (d)
F-
The Solubility product of PbCI2 is 1.7*10-5. The solubility in moles per litre would be
- (a)
1.62 * 10-2
- (b)
1.62 * 10-4
- (c)
1.62 * 10-6
- (d)
1.62 * 10-8
Conjugate base of NH4+ is
- (a)
NH3
- (b)
H2O
- (c)
NH2-
- (d)
H3+0
The dissociation constant of a weak acid HA is 4.9*10-8. The pH of its decinormal solution will be near
- (a)
3.5
- (b)
4.2
- (c)
5.3
- (d)
2.5
If a neutral solution has pKa=13.36 at 500C, the ph of the solution is
- (a)
6.68
- (b)
7
- (c)
7.63
- (d)
none
An aqueous mixture at room temperature is 0.1M with respect to ammonium chloride and 0.01M with respect to NH4OH;pKb of aqueous ammonia as a base is 5. The pH of the mixture is nearly
- (a)
7.5
- (b)
6.8
- (c)
6.5
- (d)
8
the approximate pH of a solution formed by mixing equal volumes of solutiones of 0.1M sodium propanoate and 0.1M propanoic acid (the dissociation constant pf propanoic acid is 1.3*10-5 mol dm-3) will be
- (a)
1.52
- (b)
3.62
- (c)
4.89
- (d)
15.52
A solution was prepared by mixing 50 ml of 0.2M HCI and 50 ml of 0.1M NaOH. The pH of the solution is
- (a)
2.0
- (b)
3.0
- (c)
7.0
- (d)
1.3
Which one of the following is the storngest base?
- (a)
AsNH3
- (b)
NH3
- (c)
PH3
- (d)
SbH3
Which one of the following speies cannot act both as Bronsted base as well as Lewis base?
- (a)
BF3
- (b)
\(C\overline { N } \)
- (c)
NH3
- (d)
\(N\overline { { O }_{ 3 } } \)
pH of a solution is defined by the exxpression
- (a)
log [H+]
- (b)
\(log\frac { 1 }{ \left[ { H }^{ + } \right] } \)
- (c)
\(\frac { 1 }{ log { H }^{ + } } \)
- (d)
\(-log\frac { 1 }{ { H }^{ + } } \)
The conjugate base of \({ NH }_{ 2 }^{ - }\) is
- (a)
\({ NH }_{ 3 }\)
- (b)
\({ NH }^{ 2- }\)
- (c)
\({ NH }_{ 4 }^{ + }\)
- (d)
\({ N }_{ 3 }^{ - }\)
The pH of neutral water at 25oC is 7.0. As the temperature increases, ionisation of water increases, however, the concentration of H+ and OH- ions are equal. What will be the pH of pure water at 60oC?
- (a)
Equal to 7.0
- (b)
Greater than 7.0
- (c)
Less than 7.0
- (d)
Equal to zero
If the solubility product of BaSO4 is \(15\times { 10 }^{ 10 }\) in water. Its solubility, in moles per litre, is
- (a)
\(2.5\times { 10 }^{ -9 }\)
- (b)
\(3.9\times { 10 }^{ -5 }\)
- (c)
\(7.5\times { 10 }^{ -5 }\)
- (d)
\(2.5\times { 10 }^{ -5 }\)
The first and second dissociation constants of an acid H2A are \(1.0\times { 10 }^{ -5 }\quad and\quad 5.0\times { 10 }^{ -10 }\) respectively. The overall dissociation constant of the acid will be
- (a)
\(5.0\times { 10 }^{ 5 }\)
- (b)
\(5.0\times { 10 }^{ -5 }\)
- (c)
\(5.0\times { 10 }^{ 15 }\)
- (d)
\(5.0\times { 10 }^{ -15 }\)
The ionisation constant of an acid Ka is the measure of strength of an acid. The Ka values of acetic acid, hypochlorous acid and formic acid are \(1.74\times { 10 }^{ -5 },3.0\times { 10 }^{ -8 }\quad and\quad 1.8\times { 10 }^{ -4 }\) respectively. Which of the following order of pH of 0.1 mol dm -3 solutions of these acids is correct?
- (a)
Acetic acid>hypochlorous acid>formic acid
- (b)
Hypochlorous acid>acetic acid>formic acid
- (c)
Formic acid>hypochlorous acid>acetic acid
- (d)
Formic acid>acetic acid>hypochlorous acid
Which of the following will produce a buffer solution when mixed in equal volumes?
- (a)
0.1 mol dm-3 NH4OH and 0.1 mol dm-3HCI
- (b)
0.05 mol dm-3NH4OH and 0.1 mol dm-3HCI
- (c)
0.1 mol dm-3NH4OH and 0.05 mol dm-3HCI
- (d)
01 mol dm-3CH3COONa and 0.1 mol dm-3NaOH
Four species are listed below.
I.\({HCO}^{-}_{3}\) II. \(H_{3}O^{+}\)
III. \({HSO}^{-}_{4}\) IV. \(HSO_{3}F\)
Which one of the following is the correct sequence of their acid strength?
- (a)
IV < II < III < I
- (b)
II < III < I < IV
- (c)
I < III < II < IV
- (d)
III < I < IV < II
The solubility product of a salt having general formula \(MX_{2}\) in water is \(4\times10^{-12}\) . The concentration of \(M^{2+}\) ions in the aqueous solution of the salt is
- (a)
\(4.0\times 10^{-10} \ M\)
- (b)
\(1.6 \times 10^{-4} \ M\)
- (c)
\(1.0 \times 10^{-4} \ M\)
- (d)
\(2.0 \times 10^{-6}\ M\)
Concentration of the Ag+ ions in a saturated solution of Ag2C2O4 is 2.2 x 10-4 mol-1 solubility product of Ag2C2O4 is
- (a)
2.42 x 10-8
- (b)
2.66 x 10-12
- (c)
4.5 x 10-11
- (d)
5.3 x 10-12
The solubility of AgCl(s) with solubility product 1.6 x 10-10 in 0.1 M NaCl solution would be
- (a)
1.26 x 10-5M
- (b)
1.6 x 10-9 M
- (c)
1.6 x 10-11 M
- (d)
zero
Which of the following is electron deficient?
- (a)
(CH3)2
- (b)
(SiH3)2
- (c)
(BH3)2
- (d)
PH3
Equal volumes of three acid solutions of pH 3, 4 and 5 are mixed in a vessel. What will be the H+ ion concentration in the mixture?
- (a)
1.11 x 10-4 M
- (b)
3.7 x 10-4 M
- (c)
3.7 x 10-3 M
- (d)
1.11 x 10-3 M
Calculate the pOH of a solution at 25°C that contains 1 x 10-10M of hydronium ion.
- (a)
7.00
- (b)
4.00
- (c)
9.00
- (d)
1.00
The hydrogen ion concentration of a 10-8 M HCl aqueous solution at 298 K (Kw = 10-14) is
- (a)
1.0 x 10-6 M
- (b)
1.0525 x 10-7 M
- (c)
9.525 x 10-8 M
- (d)
1.0 x 10-18 M
H2S gas when passed through a solution of cations containing HCl precipitates the cations of second group in qualitative analysis but not those belonging to the fourth group. It is because
- (a)
presence of HCl decreases the sulphide ion concentration
- (b)
presence of HCl increases the sulphide ion concentration
- (c)
solubility product of group II sulphides is more than that of group IV sulphides
- (d)
Sulphides of group IV cations are unstable in HCl
At 25°C, the dissociation constant of a base, BOH is 1.0 x 10-12 . The concentration of hydroxyl ions in 0.01 M aqueous solution of the base would be
- (a)
2.0 x 10-6 mol L-1
- (b)
1.0 x 10-5 mol L-1
- (c)
1.0 x 10-6 mol L-1
- (d)
1.0 x 10-7 mol L-1
The solubility product of a sparingly soluble salt AX2 is 3.2 x 10-11 . Its solubility (in mol/L) is
- (a)
5.6 x 10-6
- (b)
3.1 x 10-4
- (c)
2 x 10-4
- (d)
4 x 10-4