What is the redox reaction of the following case and predict its spontaneity? A chemistry teacher demonstrates a test for bromide ions by bubbling some chlorine gas cautiously through a sodium bromide solution.
1 Answer
Apr 30, 2018
Chlorine has greater electronegativity than Bromine, this results in Bromide (Br-) being oxidized and the chlorine being reduced.
Explanation:
Chlorine has a greater affinity for electrons than does bromine, so the presence of bromide ions and chlorine gas means that the extra electron possessed by the bromide would be transferred to the chlorine in a spontaneous and exothermic reaction.
the loss of the electron by bromide is the oxidation half of the reaction, the gain of the electron to become chloride is the reduction half.
Bromine liquid has a brownish colour, so the change in colour would indicate a chemical reaction has occurred (bromide would be colourless).
Cl2(g) + 2NaBr(aq) --> Br2(l) + 2NaCl(aq)
