An aqueous solution of is added slowly to an aqueous solution of as shown in List I. The variation in conductivity of these reactions is given in List II. Match List I with List II and select the correct answer using the code given below the lists:
| List I | |
|---|---|
| P. | (X to Y) |
| Q. | (X to Y) |
| R. | (X to Y) |
| S. | (X to Y) |
| List II | |
|---|---|
| 1. | Conductivity decreases and then increases |
| 2. | Conductivity decreases and then does not change much |
| 3. | Conductivity increases and then does not change much |
| 4. | Conductivity does not change much and then increases |
- (A)P-3, Q-4, R-2, S-1✓ Correct
- (B)P-4, Q-3, R-2, S-1
- (C)P-2, Q-3, R-4, S-1
- (D)P-1, Q-4, R-3, S-2
Answer: (A)
Solution
Conductometric titration patterns:
P: Weak base + weak acid → salt formation increases conductivity, then levels off → (3)
Q: (excess) + → precipitates, conductivity stays low initially, then increases as excess KI remains → (4)
R: Weak acid + strong base → neutralization decreases conductivity (H⁺ replaced by less mobile ions), then levels off → (2)
S: Strong base + strong acid → conductivity decreases (OH⁻ replaced by less mobile ions), then increases after equivalence point → (1)
Code: P-3, Q-4, R-2, S-1
P: Weak base + weak acid → salt formation increases conductivity, then levels off → (3)
Q: (excess) + → precipitates, conductivity stays low initially, then increases as excess KI remains → (4)
R: Weak acid + strong base → neutralization decreases conductivity (H⁺ replaced by less mobile ions), then levels off → (2)
S: Strong base + strong acid → conductivity decreases (OH⁻ replaced by less mobile ions), then increases after equivalence point → (1)
Code: P-3, Q-4, R-2, S-1
JEE Advanced · 2013 · 02 Jun 2013 · Paper 2 · Single correct option