General
✓✗For a given exothermic reaction, Kp and Kp′ are the equilibrium constants at temperatures T1 and T2 respectively, where T2 > T1. Assuming that the heat of reaction is constant in the temperature range between T1 and T2, it is readily observed that
- Kp < Kp′
- Kp = Kp′
- Kp > Kp′
- \( K_p = \dfrac{1}{K_p'} \)
General
✓✗In the reaction NH3 + H2O ⇌ NH4+ + OH−, water acts as
- neither an acid nor a base
- a Brönsted acid
- a Brönsted base
- a Lewis base only
General
✓✗For the equilibrium Fe(OH)3(s) ⇌ Fe3+(aq) + 3OH−(aq), if the concentration of OH− ions is decreased to one-fourth of its value, the equilibrium concentration of Fe3+ will increase by
- 64 times
- 4 times
- 16 times
- 8 times
General
✓✗The equilibrium constant Kp for the reaction MgCO3(s) ⇌ MgO(s) + CO2(g) is
- \( K_p = p_{\text{CO}_2}\times\dfrac{p_{\text{CO}_2}\times p_{\text{MgO}}}{p_{\text{MgCO}_3}} \)
- \( K_p = \dfrac{p_{\text{CO}_2}+p_{\text{MgO}}}{p_{\text{MgCO}_3}} \)
- \( K_p = \dfrac{p_{\text{MgCO}_3}}{p_{\text{CO}_2}\times p_{\text{MgO}}} \)
- Kp = pCO2
General
✓✗The addition of an inert gas at constant volume to a gaseous equilibrium mixture
- does not change the equilibrium
- increases K
- shifts it towards more moles
- shifts it towards fewer moles
General
✓✗The following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations:
A. 60 mL of 0.1 M HCl + 40 mL of 0.1 M NaOH
B. 55 mL of 0.1 M HCl + 45 mL of 0.1 M NaOH
C. 75 mL of 0.2 M HCl + 25 mL of 0.2 M NaOH
D. 100 mL of 0.1 M HCl + 100 mL of 0.1 M NaOH
The pH of which one of them will be equal to 1?
A. 60 mL of 0.1 M HCl + 40 mL of 0.1 M NaOH
B. 55 mL of 0.1 M HCl + 45 mL of 0.1 M NaOH
C. 75 mL of 0.2 M HCl + 25 mL of 0.2 M NaOH
D. 100 mL of 0.1 M HCl + 100 mL of 0.1 M NaOH
The pH of which one of them will be equal to 1?
- B
- A
- D
- C
General
✓✗In the Haber process, a temperature of about 700 K is used even though a lower temperature favours a higher equilibrium yield because
- K increases with temperature
- the rate of reaction at low temperature is too slow
- ammonia decomposes at low temperature
- the reaction is endothermic
General
✓✗For the reaction H2(g) + I2(g) ⇌ 2HI(g), the equilibrium constant Kc is
- \( \dfrac{[\text{H}_2][\text{I}_2]}{[\text{HI}]^2} \)
- \( \dfrac{[\text{HI}]^2}{[\text{H}_2][\text{I}_2]} \)
- \( \dfrac{2[\text{HI}]}{[\text{H}_2][\text{I}_2]} \)
- \( \dfrac{[\text{HI}]}{[\text{H}_2][\text{I}_2]} \)
General
✓✗An aqueous solution of AlCl3 is acidic because
- Al3+ ions hydrolyse to produce H3O+ ions
- Al3+ is a Brönsted base
- Cl− ions hydrolyse to give HCl
- AlCl3 releases OH−
General
✓✗The solubility of Mg(OH)2 (Ksp = 1.2 × 10−11) in a buffer of pH 10 is
- 1.2 × 10−3 mol L−1
- 1.2 × 10−7 mol L−1
- 1.4 × 10−4 mol L−1
- 1.2 × 10−11 mol L−1
General
✓✗For a reaction at 298 K, K = 1 × 10−3. The value of ΔG° is about (2.303RT = 5.71 kJ mol−1 at 298 K)
- +5.71 kJ mol−1
- −17.1 kJ mol−1
- +17.1 kJ mol−1
- −5.71 kJ mol−1
General
✓✗Ice and water are in equilibrium at 1 atm. The temperature of this system is
- 298 K
- 0 K
- 273 K
- 373 K
General
✓✗The pH value of blood does not appreciably change on a small addition of an acid or a base, because blood
- can be easily coagulated
- contains serum protein which acts as a buffer
- contains iron as a part of the molecule
- is a body fluid
General
✓✗For which reaction is Kp = Kc?
- 2SO2(g) + O2(g) ⇌ 2SO3(g)
- N2(g) + 3H2(g) ⇌ 2NH3(g)
- H2(g) + Br2(g) ⇌ 2HBr(g)
- PCl5(g) ⇌ PCl3(g) + Cl2(g)
General
✓✗The Ka of a weak acid is 4 × 10−10. The pH of its 0.1 M sodium salt solution is (log 5 = 0.70)
- 11.2
- 8.8
- 10.7
- 12.5