Match list-I with list-II and select the correct answer using the codes given below `:`
List-I List -II
a `CH_(3)COONa` 1. Strong electrolyte with pH `gt 7`
b. `NH_(4)Cl` 2. Strong electrolyte with the `pH lt 7`
c. `Bi_(2)S_(3)` 3. Weak electrolyte with `K_(sp) = S^(2)`
d. CdS 4. Weak electrolyte with `K_(sp) = 108 S^(5)`

Options

A. `{:(a,b,c,d),(2,3,1,4):}`
B. `{:(a,b,c,d),(1,2,4,3):}`
C. `{:(a,b,c,d),(1,3,2,4):}`
D. `{:(a,b,c,d),(1,3,4,2):}`

Answer

To solve the question of matching List-I with List-II, we will analyze each compound in List-I and determine its characteristics based on its dissociation and pH.

### Step-by-Step Solution:

1. **Identify the compounds in List-I:**
- a. CH₃COONa (Sodium acetate)
- b. NH₄Cl (Ammonium chloride)
- c. Bi₂S₃ (Bismuth sulfide)
- d. CdS (Cadmium sulfide)

2. **Analyze each compound:**

**For a. CH₃COONa:**
- CH₃COONa is a salt formed from a weak acid (acetic acid, CH₃COOH) and a strong base (sodium hydroxide, NaOH).
- It dissociates completely in solution, making it a strong electrolyte.
- Since it is a salt of a weak acid and a strong base, it will have a basic nature, resulting in a pH greater than 7.
- **Match:** a → 1 (Strong electrolyte with pH > 7)

**For b. NH₄Cl:**
- NH₄Cl is a salt formed from a strong acid (HCl) and a weak base (ammonium hydroxide, NH₄OH).
- It also dissociates completely in solution, making it a strong electrolyte.
- Being a salt of a strong acid and a weak base, it will have an acidic nature, resulting in a pH less than 7.
- **Match:** b → 2 (Strong electrolyte with pH < 7)

**For c. Bi₂S₃:**
- Bi₂S₃ does not dissociate completely in solution, making it a weak electrolyte.
- The solubility product (Ksp) can be calculated based on the dissociation into ions.
- The Ksp expression for Bi₂S₃ is Ksp = [Bi³⁺]²[S²⁻]³.
- If we let the solubility of Bi₂S₃ be 'S', then Ksp = (2S)²(3S)³ = 4S² * 27S³ = 108S⁵.
- **Match:** c → 4 (Weak electrolyte with Ksp = 108S⁵)

**For d. CdS:**
- CdS also does not dissociate completely, making it a weak electrolyte.
- The Ksp expression for CdS is Ksp = [Cd²⁺][S²⁻].
- If we let the solubility of CdS be 'S', then Ksp = S * S = S².
- **Match:** d → 3 (Weak electrolyte with Ksp = S²)

3. **Final Matching:**
- a → 1
- b → 2
- c → 4
- d → 3

### Conclusion:
The correct answer is:
- a → 1
- b → 2
- c → 4
- d → 3