471.

Equimolar solutions of the following  were prepared in water separately which one of the solutions will record the highest pH? 

• SrCl₂

• BaCl₂

• MgCl₂

• MgCl₂

The dissociation equilibrium  of gas AB₂ can be represented as

2AB₂ (g) ⇌ 2AB (g) + B₂ (g)
The degree of dissociation is 'x' and is small compared to 1. The expression relating the degree of dissociation  (x) with equilibrium constant K_p and total pressure p is 

• (2K_p / p)

• (2K_p/p)^1/3

• (2K_p/p)^1/2

• (2K_p/p)^1/2

The value of K_P1 and K_p2 for the reactions

X ⇌ Y +Z  ... (i)
A ⇌ 2B    ... (ii)

are in the ratio of 9:1. if the degree of dissociation of X and A be equal, then the total pressure at equilibrium (i) and (ii) are in the ratio

• 3:1

• 1:9

• 36:1

• 36:1

The value of equilibrium constant of the reaction HI (g) ⇌ H₂(g)/2 + I₂/2 is 8.0
The equilibrium constant of the reaction H₂(g) + I₂(g) ⇌ 2 HI (g)  will be

• 1/16

• 1/64

• 16

• 16

Calculate the pOH of a solution at 25⁰C that contains 1 x 10^-10 M of hydronium ions.

• 7

• 4

• 9

• 9

A Weak acid, H_A has a K_a of 1.00 x 10^-5. If 0.100 mole of this percentage of acid dissociated at equilibrium is closest to:

• 99.0%

• 1.00%

• 99.9 %

• 99.9 %

The following equilibrium constants are given:

N₂ + 3H₂  ⇌ 2NH₃; K₁

N₂ +O₂  ⇌ 2NO; K₂

H₂ + 1/2O₂  ⇌ H₂O' K₃

The equilibrium constants for the oxidation of NH₃ by oxygen to give NO is:

• K₂K₃³ /K₁

• KK₂K₃² /K₁

• K₂²K₃ /K₁

• K₂²K₃ /K₁

Identify the correct statement for the change of Gibbs energy for a system (ΔG_system) at constant temperature and pressure

• If ΔG_system > 0, the process is spontaneous

• If ΔG_system =0, the system has attained equilibrium

• If ΔG_system < 0, the system is still moving in a particular direction
  

• If ΔG_system < 0, the system is still moving in a particular direction
  

The enthalpy and entropy change for the reaction:

Br₂ (l) + Cl₂ (g)→ 2BrCl (g)

are 30 kJ mol^-1 and 105 JK^-1 mol^-1 respectively. The temperature at which the reaction will be in equilibrium is:

• 285.7 K 

• 273 K

• 450 K

• 450 K

For the reaction,

CH₄  (g) + 2 O₂ (g) ⇌ CO₂ (g) + 2H₂O (l), 

Δ_rH = - 170. 8 kJ mol^-1

Which of the following statements is not true? 

• At equilibrium, the concentrations of CO₂ (g) and H₂O (l) are not equal

• The equilibrium constant for the reaction is given by K_p = 

• Addition of CH₄ (g) or O₂ (g) at equilibrium will cause a shift to the right

• Addition of CH₄ (g) or O₂ (g) at equilibrium will cause a shift to the right