For a given exothermic reaction, Kp and Kp’ are the equilibrium constants at temperatures T1 and T2 respectively. Assuming that the heat of reaction is constant in temperatures range between T1 and T2, it is readily observed that:
1.
2.
3.
4.
Which of the following species is least likely to act as a Lewis base?
1. F–The strongest acid among the following compounds is:
| 1. | HClO3 | 2. | HClO4 |
| 3. | H2SO3 | 4. | H2SO4 |
Find the solubility product (Kₛₚ) of Ba(OH)₂ if the pH of its saturated solution is 12.
1. 3.3 × 10⁻⁷
Which of the following equimolar solutions, prepared separately, will have the highest pH?
| 1. | \(\mathrm{B a C l_{2}}\) | 2. | \(\mathrm{A l C l_{3}}\) |
| 3. | \(\mathrm{L i C l}\) | 4. | \(\mathrm{B e C l_{2}}\) |
Buffer solutions have constant acidity and alkalinity because:
| 1. | these give unionized acid or base on reaction with added acid or alkali. |
| 2. | acid and alkali in these solutions are shielded from attack by other ions |
| 3. | they have large excess of H+ or OH- ions |
| 4. | they have fixed value of pH |
A buffer solution is prepared in which the concentration of NH3 is 0.30 M and the concentration of is 0.20 M. If the equilibrium constant, Kb for NH3 equals 1.8×10–5, then what is the pH of this solution?
(log 1.8 = 0.25; log 0.67 = –0.176)
1. 9.43
2. 11.72
3. 8.73
4. 9.08
What conditions favor the formation of 2XY₄(g) in the reaction X₂(g) + 4Y₂(g) ⇋ 2XY₄(g), considering that the enthalpy change (ΔH) is negative?
1. Low pressure and low temperature
2. High temperature and low pressure
3. High pressure and low temperature
4. High temperature and high pressure
Find the equilibrium constant K for the reaction:
NO₂(g) ⇌ ½N₂(g) + O₂(g)
Given:
N₂(g) + O₂(g) ⇌ 2NO(g), K₁
2NO(g) + O₂(g) ⇌ 2NO₂(g), K₂
1. 4K₁K₂Calculate the hydrogen ion concentration, [\(\text{H}^+\)] (in \(\text{mol}/\text{L}\)), of a buffer solution prepared by mixing \(0.10 \text{ M}\) acetic acid (\(\text{CH}_3\text{COOH}\)) and \(0.20 \text{ M}\) sodium acetate (\(\text{CH}_3\text{COONa}\)), given that the acid dissociation constant (\(\text{K}_a\)) for acetic acid is \(1.8 \times 10^{-5}\):
1. \(3 . 5 \times 10^{- 4}\)
2. \(1 . 1 \times 10^{- 5}\)
3. \(1 . 8 \times 10^{- 5}\)
4. \(9 . 0 \times10^{- 6}\)