451.

Given the reaction between two gases represented by A₂ and B₂ to give the compound AB (g).
A₂(g) +B₂ (g)  ⇌ 2AB (g)
At equilibrium the concentration
of A₂ = 3.0 x 10^-3 M
of B₂ = 4.2 x 10^-3 M
of AB = 2.8 x 10^-3 M

If the reaction takes place in a sealed vessel at 527^oC, then the value of K_c will be

• 2.0

• 1.9

• 0.62

• 0.62

A buffer solution is prepared in which the concentration of NH₃ is 0.30 M and the concentration of NH₄ is 0.20 M. If the equilibrium constant, K_b for NH₃ equals 1.8 x 10^-5, what is the pH of this solution?

log ( 2.7 = 0.43)

• 9.43

• 11.72

• 8.73

• 9.08

The value of ΔH for the reaction

X₂ (g) + 4Y₂ (g) ⇌ 2XY₄ (g) is less than zero. Formation of XY4 (g) will be favoured at

• Low pressure and low temperature

• high temperature and low pressure

• high pressure and low temperature

• high pressure and low temperature

For the reaction N₂ (g) + O₂ (g) ⇌  2NO (g), the equilibrium constant is K₁. The equilibrium constant is K₂ for the reaction 2NO (g) + O₂(g) ⇌ 2NO₂ (g). What is K for the reaction 

• 1/(4K₁K₂)

• [1/K₁K₂]^1/2

• 1/(K₁K₂)

• 1/(K₁K₂)

What is the pH of the resulting solution when equal volumes of 0.1 M NaOH and 0.01 M HCl are mixed?

• 12.65

• 2.0

• 7.0

• 7.0

Which one of the following pairs of the solution is not an acidic buffer?

• HClO₄ and NaClO₄

• CH₃COOH and CH₃COONa

• H₂CO₃ and Na₂PO₄

• H₂CO₃ and Na₂PO₄

If the equilibrium constant for 

• K^1/2

• K/2

• K 

• K 

An aqueous solution of which of the following compounds is the best conductor of electric current?

• Acetic acid C₂H₄O₂

• Hydrochloric acid, HCl

• Ammonia, NH₃

• Ammonia, NH₃

If pH ofa saturated solution of Ba(OH)₂ is 12, the value of its K_sp is 

• 4.00 x 10^-6 M³

• 4.00 x 10^-7 M³

• 5.00 x 10^-6 M³

• 5.00 x 10^-6 M³

What is [H⁺] in mol/L of a solution that is 0.20 M in CH₃COONa and 0.10 M in CH₃COOH? 
(K_a for CH₃COOH = 1.8 x 10^-5 )

• 3.5 x 10^-4

• 1.1 x 10^-5

• 1.8 x 10^-5

• 1.8 x 10^-5