A sample of water drawn from a river passing through an agricultural district was divided into two portions. The first portion gave a white precipitate when acidified barium chloride was added. The second portion when warmed with aqueous sodium hydroxide gave a colourless gas which turned a moist red litmus paper blue.
(a) Identify the ions present in the river water.
(b) Suggest the possible source(s) of the ions identified in (a) above.

Answer:

a)#SO^(2-) and NH_4^+#
b)From ammonia and sulphate based fertilizer used in the farms.

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