Bimonthly Test

A gas X dissociates on heating to set up the equilibrium below.

X = Y +Z

A quantity of X was heated at constant pressure p at a certain temperature . The equilibrium partial pressure of X was found to be 1/7 p . What is the equilibrium constant K_p at this temperature?

• 6/7 p

• 9/7 p

• 36/7p

• 6p

In the mixture of NO and CO2 (initially containing 4 mol of NO and 0.9 mol of CO2) reaction occurs according to the equation below.

NO+ CO2 = NO2 + CO

At equilibrium 0.1 mol of CO2 was present . What is the equilibrium constant, Kc at the temperature of this experiment?

• 0.2

• 0.5

• 1.6

• 2.0

Which one of the following affects the value of the solubility product Ksp of silver sulphide when it is precipitated by passing hydrogen sulphide into aqueous silver nitrate?

• An increase in the temperature

• The addition of aqueous sodium sulphate

• The addition of aqueous silver nitrate

• The presence of an excess of acid

An acidified solution containing 0.1 M of zinc sulphate and 0.1 M of copper (II) sulphate is saturated with hydrogen sulphide at 15 ⁰C . The concentration of S^-2 in the solution is then 10 ^-35 M.

The solubility product of zinc sulphide at 15 ⁰C is 10 ^-24 M² and then copper (II) sulphide is

10 ^-40 M² .

Which statement describes what happens in the solution?

• No precipitate is formed

• Copper (II) sulphide only is precipitated

• Copper (II) sulphide is precipitated followed by Zinc sulphide

• Zinc sulphide is precipitated followed by copper (II) sulphide

If the equilibrium is established by initially adding 0.10 mol each of A and B to a 1L container, then which of the following must be true once the mixture achieves equilibrium?

A + 2B = 2C K = 320

• [A] = [B]

• [A] = [B] = [C]

• [B] = 2[C]

• [A] > [B]

A reaction X + 2Y → 3Z is started with 1.0 M Z and no X or Y. To calculate the equilibrium concentrations of all species using an ICE table, which of the following would you enter in the Z column for the C row?

• 1.0 M

• 1.0 M + 3x

• –3x

• +3x

The addition of HCl does not suppress the dissociation of:

• Acetic acid

• benzoic acid

• Hydrogen Sulphide

• Sulphuric acid

In which of the following the solubility of AgCl is minimum?

• 0.1M NaNO3

• Water

• 0.1 M NaCl

• 0.1 M NaBr

If 200 mL of 1x10^–7 M AgNO₃ is mixed with 200 mL of 1x10^–8 M NaI, what will occur? For AgI, Ksp = 8.3 x 10^–17 .

• No precipitate will form.

• Silver(I) nitrate will precipitate

• Silver(I) iodide will precipitate.

• Sodium nitrate will precipitate

What is the specific heat capacity of a substance if 2.41x10⁴ J are needed to change the temperature of 105.0 g of it from 25.0ºC to 250.0ºC?

• 1.02 x 10^-4 J/gºC

• 9.18 x 10^-4 J/gºC

• 0.918 J/gºC

• 1.02 J/gºC