Determination of Second Dissociation Constant of 7 -nitro-8-quinolinol-5-sulphonic Acid by EMF Method
| Main Authors: | S. K. PATEL, K. P. SONI, I. M. BHAT |
|---|---|
| Format: | Article Journal |
| Bahasa: | eng |
| Terbitan: |
, 1972
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/6425214 |
Daftar Isi:
- Chemistry Department, Gujarat University, Ahmedabad-9 Received 20 July 1971; accepted for publication 11 February 1972 7-nitro-8-quinolinol-5-sulphonic acid is dibasic. From the preliminary investigation, it was found that the ratio of kD1 /kD2 was greater than 103 . Hence the treatment of monobasic acid to determine pkD may be applied to the second stage of dissociation constant. The titration technique was used to determine Bronsted constant ( Dk' D2 ), using Henderson equation. pk'D2 was determined at various ionic strenghs. The graph of pk'D2 against VI was plotted. The limiting slope of the curve was found to be -1.58, agreeing well with the theoretical value of -1.57 at 40°. The thermodynamic value of pkD4 obtained on extrapolation to zero ionie strength is 5.72 ± 0.02.