Question

(i) Copper wire, (ii) Sulphur, (iii) Aluminium sheet, (iv) Iron nail, (v) Iodine crystal Answer the following: (a) Classify them into metals and nonmetals (b) Iron nail has a brown layer why is it so? (c) Which one is a better conductor of heat? (d) Write down the reaction of metals with water. (e) Write down the reactions of nonmetals with water.

Answer 1

a) metals : copper wire, aluminium sheet, iron nail
    non- metals : sulphur, iodine crystal
b) brown layer on the iron nail is due to formation of rust i.e. iron oxide is formed.
c) Copper is better conductor
d) copper doesn't react with water. It reacts with oxygen.  2 Cu + O2 → 2        CuO
    Al3+(aq) + 6H2O(l) ↔ [Al(H2O)6]3+ (aq)    4 Fe + 3 O2 + 6 H2O → 4 Fe3+ + 12 OH →4 Fe(OH)3
e) Sulphur does not react with normally.
    iodine reacts with water to give hypoiodites