Question

In Saltzman method, which of the following are formed when air containing NO2 is passed in an absorbing solution consisting of the sulphanilic acid and diamine dissolved in the acetic acid medium?

(a) Blue colour dye complex

(b) Green colour dye complex

(c) Pink colour dye complex

(d) Orange colour dye complex

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I want to ask this question from Estimation of Nitrogen Oxides in section Pollution Monitoring Instruments of Analytical Instrumentation

Answer 1

The correct answer is (c) Pink colour dye complex

Best explanation: In Saltzman method, a pink colour dye is formed when air containing NO2 is passed in an absorbing solution consisting of the sulphanilic acid and diamine dissolved in the acetic acid medium. It is sensitive in the ppm range.