Write down the correct increasing order of flocculation value
a. `NaCl, CaCl_(2), AlCl_(3)`
b. `KBr, K_(2)C_(2)O_(4), K_(3)[Fe(CN)_(6)], K_(4)[Fe(CN)_(6)]`.

Answer

To determine the correct increasing order of flocculation values for the given electrolytes, we need to understand the relationship between flocculation value and the valency of the ions involved. The flocculation value is the minimum concentration of an electrolyte required to cause coagulation or flocculation of colloidal particles, and it is inversely proportional to the valency of the ions.

### Part (a): NaCl, CaCl₂, AlCl₃

1. **Identify the valency of ions:**
- NaCl: Na⁺ (valency = 1), Cl⁻ (valency = 1)
- CaCl₂: Ca²⁺ (valency = 2), Cl⁻ (valency = 1)
- AlCl₃: Al³⁺ (valency = 3), Cl⁻ (valency = 1)

2. **Determine the flocculation values:**
- Since the flocculation value is inversely proportional to the valency, we can rank them based on the cation's valency:
- AlCl₃ has the highest valency (3), hence it has the lowest flocculation value.
- CaCl₂ has a valency of 2, so it has a higher flocculation value than AlCl₃ but lower than NaCl.
- NaCl has the lowest valency (1), thus it has the highest flocculation value.

3. **Increasing order of flocculation values:**
- AlCl₃ < CaCl₂ < NaCl

### Part (b): KBr, K₂C₂O₄, K₃[Fe(CN)₆], K₄[Fe(CN)₆]

1. **Identify the valency of anions:**
- KBr: Br⁻ (valency = 1)
- K₂C₂O₄: C₂O₄²⁻ (valency = 2)
- K₃[Fe(CN)₆]: [Fe(CN)₆]³⁻ (valency = 3)
- K₄[Fe(CN)₆]: [Fe(CN)₆]⁴⁻ (valency = 4)

2. **Determine the flocculation values:**
- Again, since the flocculation value is inversely proportional to the valency of the anion:
- K₄[Fe(CN)₆] has the highest valency (4), hence it has the lowest flocculation value.
- K₃[Fe(CN)₆] has a valency of 3, so it has a higher flocculation value than K₄[Fe(CN)₆] but lower than K₂C₂O₄.
- K₂C₂O₄ has a valency of 2, thus it has a higher flocculation value than K₃[Fe(CN)₆].
- KBr has the lowest valency (1), so it has the highest flocculation value.

3. **Increasing order of flocculation values:**
- K₄[Fe(CN)₆] < K₃[Fe(CN)₆] < K₂C₂O₄ < KBr

### Final Answers:
- (a) AlCl₃ < CaCl₂ < NaCl
- (b) K₄[Fe(CN)₆] < K₃[Fe(CN)₆] < K₂C₂O₄ < KBr