In West-Gaeke colourimetric procedure, the intensity of the red purple colour is measured photometically and it is proportional to the concentration of sulphur di-oxide. What is the red purple coloured compound?
A. Sodium tetra chloromercurate
B. Dicholorosulphitomercurate complex
C. Ammonia molybdate
D. Paraosaniline sulphonic acid
Answer:D
In West-Gaeke colourimetric procedure, the intensity of the red purple colour is measured photometically and it is proportional to the concentration of sulphur di-oxide. What is the red purple coloured compound?
A. Sodium tetra chloromercurate B. Dicholorosulphitomercurate complex C. Ammonia molybdate D. Paraosaniline sulphonic acid
Explanation: Sulphur di-oxide reacts with Sodium tetra chloromercurate to form Dicholorosulphitomercurate complex which then reacts with formaldehyde and pararosaniline to form Parapsaniline sulphonic acid which is red purple coloured.