Electrolysis of aqueous Sodium Chloride

Products produced by a molten electrolyte is easy when we know the cation and the anion. cation will be involving in the cathode reaction and the anion will be involving in the anodic reaction.

e.g Electrolysis of molten sodium chloride

Molten Sodium chloride contains Sodium ions which will produce sodium in the cathode,

Na⁺ +e  ---> Na

and chloride ions which will produce chlorine gas in the anode

2Cl^-  -2e ---> Cl₂

When the electrolysis of aqueous solution is considered the products produced in the anode and the cathode will be different as there are more than one ions present in the both anode and the cathode

e.g Electrolysis of aqueous Sodium chloride

In a solution of aqueous solution of Sodium chloride there are four types of ions. In addition to the Sodium (Na⁺ )and chloride (Cl^-) ions there will be Hydrogen ( H+) and hydroxide (OH-) ions.

To the positive electrode Both the negative ions will be attracted. Most reactive anion (anions at higher positions of electro chemical series will discharge first. From Chloride and hydroxide ions in a concentrated aqueous solution the chloride ions will discharge and produce chlorine gas.

To the negative electrode both the Sodium and hydrogen ions will be attracted. here in this electrode the least reactive ion (According the reactivity series) will discharge first. Hydrogen will be produced by the discharge of Hydrogen ions. 

Ionic Bonding

Ionic bond is a bond between a metal and a non metal. Metals are elements with shiny surfaces, sonorous sounds, malleable and with good conductors of heat and electricity.

Metals usually have upto 3 electrons in their outer most shell (in non transitional elements). To achieve the noble gas configuration they would release these electrons and become positive ions.
Non metals in the other hand (mainly group V,VI,VII elements in the periodic table) has 5, 6 or 7 electrons in their outermost shell. In order to achieve a stable electronic configuration these elements can accept electrons and become negative ions. Electrostatic attraction between a positive ion and a negative ion makes ionic bonding.

compounds with ionic bonds are having properties such as high melting points, boiling pointsand readily soluable in water .

Next about covalent bonding