Give reason for the following: (a) Silver nitrate solution is kept in coloured bottles.
(b) Molybdenum is used in the manufacture of ammonia.
(c) Blue solution of copper sulphate changes to green when a piece of iron is added to this solution.​

a) In the presence of light silver nitrate decompose to form silver. hence to prevent the decomposition it is kept in dark coloured bottles.

b) Molybdenum is used in the manufacture of ammonium because molybdenum acts as a promoter which increases the efficiency of the catalyst Iron, resulting in better yield of ammonia.

c) When an iron nail immersed in the solution of copper sulphate than iron displaces copper from the solution of copper sulphate because iron is more reactive than copper. Therefore copper sulphate solution colour changes from blue to pale green.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.