A metal salt MX when exposed to light splits up to form metal M and a gas X2. Metal M is used in making ornaments whereas gas X2 is used in making bleaching powder. The salt MX is itself used in black and white photography.
(a) What do you think metal M is?
(b) What could be gas X2?
(c) Name the metal salt MX.
(d) Name any two salt solutions which on mixing together can produce a precipitate of salt MX.
(e) What type of chemical reaction takes place when salt MX is exposed to light? Write the equation of the reaction.
(a) Metal M is Silver.
(b) Gas X2 is chlorine.
(c) Salt MX is Silver Chloride.
(d) Silver Nitrate and Sodium chloride on mixing together produce the same precipitate as MX.
(e) Decomposition reaction takes place.
The chemical equation:
2AgCl (s) 
2Ag (s) + Cl2 (g)
67