pKa values of three acids A, B and C are 4.3, 3.3 and 5.5 respectively. Which of the following represents the correct order of acid strength?
1. A>B>C
2. C>A>B
3. B>A>C
4. C>B>A
Which of the following statements are correct?
| I. | The pH of \(1.0 \times 10^{-8}~ \text M\) solution of HCl is 8. |
| II. | The conjugate base of \(\text H_2 \text {PO}^-_4\) is \(\text {HPO} ^{2-}_4\) |
| III. | The autoprotolysis constant of water increases with temperature. |
| IV. |
At the half-neutralization point in the titration of a weak monoprotic acid with a strong base, the pH equals the (1/2) pKa of the acid |
1. II, and III
2. I, II, and III
3. III, and IV
4. II, III, and IV
The solubility of is y mol dm-3. Its solubility product is
1.
2.
3.
4.
If for fluoride ion at is 10.83, the ionization constant of hydrofluoric acid at this temperature is:
1.
2.
3.
4.
The pKa of HCN is 9.30. The pH of a solution prepared by mixing 2.5 moles of KCN and 2.5 moles of HCN in water and making up the total volume to 500 ml will be:
| 1. | 9.30 | 2. | 8.30 |
| 3. | 7.30 | 4. | 10.30 |
What is the decreasing order of strength of the bases?
1.
2.
3.
4.
The following equilibrium is established when hydrogen chloride is dissolved in acetic acid:
\(\small {\mathrm{HCl}+\mathrm{CH}_3 \mathrm{COOH} \rightleftharpoons \mathrm{Cl}^{-}+\mathrm{CH}_3 \mathrm{COOH}_2^{+}}\)
The set that characterizes the conjugate acid-base pair is:
| 1. | \(\small {(HCl, CH_3COOH) ~\text {and}~ (CH_3COOH_2^+ , Cl^-)}\) |
| 2. | \(\small { (HCl, CH_3COOH_2^+)~ \text {and} ~(CH_3COOH, Cl^-)}\) |
| 3. | \(\small {(CH_3COOH^+_2 , HCl)~ \text {and} ~(Cl^-, CH_3COOH) }\) |
| 4. | \(\small {(HCl, Cl^-) \text {and}~(CH_3COOH_2^+ , CH_3COOH)}\) |
Which of the following is an example of a reversible reaction?
| 1. | \(\small{KNO_3(aq) + NaCl(aq) \rightleftharpoons KCl(aq) + NaNO_3(aq)} \) |
| 2. | \(\small{2Na(s) + H_2O(l) \rightleftharpoons 2NaOH(aq) + H_2(g)} \) |
| 3. | \(\small{AgNO_3(aq) + NaCl(aq) \rightleftharpoons AgCl(s) + NaNO_3(aq)} \) |
| 4. | \(\small{Pb{(NO_3)}_2(aq) + 2NaI(aq) \rightleftharpoons PbI_2(s) + 2NaNO_3(aq)} \) |
A certain weak acid has a dissociation constant of The equilibrium constant for its reaction with a strong base is
1.
2.
3.
4.
The precipitate of CaF2 is obtained when equal volumes of the following are mixed
1.
2.
3.
4.