Equilibrium

Equilibrium
Class:XI / Unit:7

1. Which of the following aqueous solution will be the best conductor of electricity?

C₆H₁₂O₆
NH₃
HCl
CH₃COOH

2. Highest pH will be recorded for which of the following solutions if they are equimolar

LiCl
BaCl₂
BeCl₂
AlCl₃

3. On increasing the concentration of reactants in a reversible reaction, then equilibrium constant will

increase
decrease
unchanged
depend on the concentration

4. Find the conjugate acid of NH₂^–

NH₄OH
NH₄⁺
NH₂^–
NH₃

5. Buffer solutions have constant acidity and alkalinity because

Acids and alkalies in these solutions are shielded from attack by other ions
They have fixed value of pH
These give unionised acid or base on reaction with added acid or alkali
They have large excess of H⁺ or OH^– ions

6. The solubility of Ca₃(PO₄)₂ in water is y moles/litre. Its solubility product is

36y⁴
108y⁵
6y⁴
64y⁵

7. 0.023 g of sodium metal is reacted with 100 cm3 of water. The pH of the resulting solution is

12
10
9
8

8. What is the best description of the change that occurs when Na₂O(s) is dissolved in water?

Oxidation number of sodium decreases
Oxide ion donates a pair of electrons
Oxide ion accepts sharing in a pair of electrons
Oxidation number of oxygen increases

9. Passing H₂S gas into a mixture of Mn²⁺, Ni²⁺, Cu²⁺ and Hg²⁺ ions in an acidified aqueous solution precipitates

CuS and HgS
MnS and CuS
MnS and NiS
NiS and HgS

10. If, in the reaction N₂O₄ ⇌ 2NO₂, x is that part of N₂O₄ which dissociates, then the number of molecules at equilibrium will be

1
3
(1 + x)
(1 + xy)²