The pH of neutral water at is 7.0. As the temperature increases, ionisation of water increases. However, the concentration of H+ ions and OH- ions is equal. The pH of pure water at is:
1. | Equal to 7.0 | 2. | Greater than 7.0 |
3. | Less than 7.0 | 4. | Equal to zero |
The ionisation constant of an acid, Ka , is the measure of the strength of an acid. The Ka values of acetic acid, hypochlorous acid and formic acid are and , respectively. The correct order of pH value of 0.1 mol dm-3 solutions of these acids is -
1. Acetic acid > hypochlorous acid > formic acid
2. Hypochlorous acid < acetic acid > formic acid
3. Formic acid > hypochlorous acid > acetic acid
4. Formic acid < acetic acid < hypochlorous acid
are the respective ionisation constants for the following reactions.
\(\mathrm{H}_2 \mathrm{~S} \rightleftharpoons \mathrm{H}^{+}+\mathrm{HS}^{-}\)
\(\mathrm{HS}^{-} \rightleftharpoons \mathrm{H}^{+}+\mathrm{S}^{2-}\)
\(\mathrm{H}_2 \mathrm{~S} \rightleftharpoons 2 \mathrm{H}^{+}+\mathrm{S}^{2-}\)
The correct relationship between is:
1. | \(\mathrm{K}_{\mathrm{a}_3}=\mathrm{K}_{\mathrm{a}_1} \times \mathrm{K}_{\mathrm{a}_2} \) | 2. | \(\mathrm{K}_{\mathrm{a}_3}=\mathrm{K}_{\mathrm{a}_1}+\mathrm{K}_{\mathrm{a}_2} \) |
3. | \(K_{a_3}=K_{a_1}-K_{a_2} \) | 4. | \(\mathrm{K}_{\mathrm{a}_3}=\mathrm{K}_{\mathrm{a}_1} / \mathrm{K}_{\mathrm{a}_2}\) |
Acidity of BF3 can be explained on the basis of:
1. Arrhenius concept
2. Bronsted Lowry concept
3. Lewis concept
4. Bronsted Lowry as well as Lewis concept
The mixture that will produce a buffer solution when mixed in equal volumes is:
1. | 0.1 mol dm-3 NH4OH and 0.1 mol dm-3 HCl |
2. | 0.05 mol dm-3 NH4OH and 0.1 mol dm-3 HCl |
3. | 0.1 mol dm-3 NH4OH and 0.05 mol dm-3 HCl |
4. | 0.1 mol dm-3 CH3COONa and 0.1 mol dm-3 NaOH |
Among the following solvents, silver chloride is most soluble in:
1. solution
2. solution
3.
4. Aqueous ammonia
The value of the pH of \(0.01 \) \(\text{mol dm}^{-3} \)\(\text{CH}_3\text{COOH}\) \(\left(K_a=1.74 \times 10^{-5}\right)\) is:
1. | 3.4 | 2. | 3.6 |
3. | 3.9 | 4. | 3.0 |
for is and Kb for is . The pH of ammonium acetate will be:
1. 7.005
2. 4.75
3. 7.0
4. Between 6 and 7
Which of the following alternatives best describes the reaction A ⇌ B at its halfway point?
1. | \(\Delta G^{\ominus}=0\) | 2. | \(\Delta G^{\ominus}>0\) |
3. | \(\Delta G^{\ominus}<0\) | 4. | \(\Delta G^{\ominus}=-RTlnK\) |
On increasing the pressure, the direction in which the gas phase reaction proceeds to re-establish equilibrium is predicted by applying Le-Chatelier's principle. Consider the reaction,
Which of the following is correct, if the total pressure at which the equilibrium is established is increased without changing the temperature?
1. | K will remain the same. |
2. | K will decrease. |
3. | K will increase. |
4. | K will increase initially and then decrease, when pressure is very high. |