Question

The dilution of solution must not reduce the level of ammonia below _________

(a) 10^-2 M

(b) 10^-5 M

(c) 10^-8 M

(d) 10^-9 M

The question was posed to me in semester exam.

Enquiry is from Ammonia and Fluoride Electrode topic in section pH Meters and Ion Analysers of Analytical Instrumentation

Answer 1

The correct option is (b) 10^-5 M

The best I can explain: The dilution of solution must not reduce the level of ammonia below 10^-5 M. The total level of dissolved species must be below 1M.