Give reason for the following :
Carbon tetrachloride is liquid but does not conduct electricity.
Explain the following briefly: (a) Sodium chloride dissolves in water but carbon tetrachloride is insoluble in water. (b) Helium does not form He2 molecule. (c) Pure water does not conduct electricity, but on adding sodium chloride to it, it starts conducting electricity. (d) Cl2 is a non-polar molecule, while HCl is a polar molecule. (e) Metals are electropositive.
(a) State one appropriate observation for: Electricity is passed through molten lead bromide.
(b) State which of these will act as a non-electrolyte
(i) Liquid carbon tetrachloride
(ii) Acetic acid
(iii) Sodium hydroxide aqueous solution
(iv) Potassium chloride aqueous solution
(c) Copper sulphate soln. is electrolysed using copper electrodes.
(i) Which electrode to your left or right is known as the oxidising electrode and why ?
(ii) Write the equation representing the reaction that occurs.
(iii) State two appropriate observations for the above electrolysis reaction.
(d) Identify : A gas which does not conduct electricity in the liquid state but conducts electricity when dissolved in water.