A metal E is stored under kerosene. When a small piece of it is left open in the air, it catches fire. When the product formed is dissolved in water it turns red litmus to blue : (i) Name the metal E. (ii) Write the chemical equation for the reaction when it is exposed to air and when the product is dissolved in water. (iii) Explain the process by which the metal is obtained from its molten chloride.
A metal E is stored under kerosene. When a small piece of it is left open in the air, it catches fire. When the product formed is dissolved in water it turns red litmus to blue : (i) Name the metal E. (ii) Write the chemical equation for the reaction when it is exposed to air and when the product is dissolved in water. (iii) Explain the process by which the metal is obtained from its molten chloride.
Dear student!
i). The metal is Potassium (K), as it reacts very fast with air and catches fire.
ii). K + O2 -> K2O(potassium superoxide)
K2O + H2O --> 2KOH (potassium hydroxide ; a base which converts litmus paper to blue)
iii). The extraction of metal from its molten salt is done by electrolysis from KCl (potassium chloride)
At cathode: K+ + e- -> K
At anode: Cl -> : Cl- + e-
Over all reaction : KCl -> K+ + Cl-
Dear student!
i). The metal is Potassium (K), as it reacts very fast with air and catches fire.
ii). K + O2 -> K2O(potassium superoxide)
K2O + H2O --> 2KOH (potassium hydroxide ; a base which converts litmus paper to blue)
iii). The extraction of metal from its molten salt is done by electrolysis from KCl (potassium chloride)
At cathode: K+ + e- -> K
At anode: Cl -> : Cl- + e-
Over all reaction : KCl -> K+ + Cl-
