Sodium Chloride: Chemistry and Uses

Bleaching powder $(CaOCl _2)$ has many uses and some of them are as follows :-

Calcium hydroxide on reaction with chlorine produces bleaching powder. 

The well-known table salt is chemically sodium chloride. Its chemical formula is $NaCl$.

The ionization of salt:

$NaCl\rightarrow Na^{+}+Cl^{-}$

The half-reaction at the cathode is:

$H _2O+2e^{−}\rightarrow H _2+2OH^{−}$

Here, the reduction is taking place.

The half-reaction at the anode is:

$2Cl^{-}\rightarrow Cl _2+1e^{−}$

Here, oxidation is taking place.

The overall reaction is as follows:

As NaCl is ionic compound so in molten states it will form $Na^+$ and $Cl^-$ ion and these ions conduct electricity.

Sea water contains $MgCl _2$ brine so salt made from sea water contains this as impurity.
sea salt:

$NaOH \xrightarrow {heat} $ no reaction
$NaNO _3 \xrightarrow {heat} NaNO _2+\frac{1}{2}O _2$

Commercial common salt commonly becomes slightly damp on keeping because common salt contains some impurities like ${MgCl _2}$ and ${CaCl _2}$ which are hygroscopic in nature and absorb moisture from the atmosphere.
Hence, option B is correct.

Hargreaves process:
$ 4NaCl (s) + 2SO _2 (g) + 2H _2O (g) + O _2 (g) \longrightarrow 2Na _2SO _4 + 4HCl $

The reaction of non-metals with bases is complex. Example: When chlorine reacts with a base like sodium hydroxide, it gives multiple products like sodium hypochlorite, sodium chloride and water.

The common table salt is prepared by passing HCI gas through a saturated solution of salt. The precipitation is due to common ion effect.

Option (B) is correct.

Statement 1: Crystals of sodium chloride go into aqueous solution as ions.
$\displaystyle NaCl \rightleftharpoons Na^+ (aq) + Cl^- (aq) $
Statement 2: The sodium ion has a $1+$ change and the chloride ion has a $1−$ charge and they are hydrated by the water molecules.
Each sodium ion ( or each chloride ion) is surrounded by several water molecules.
Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.

The high melting point (801 C) and excellent conductivity in aqueous solution are characteristic of an ionic compound. Sodium chloride (NaCl) is a classic ionic solid that fits these properties perfectly.

In crystalline solids, the ions are tightly bound by strong coulombic force of attraction having greater interatomic interaction and less interparticle space. $ { Na }^{ + }$ and ${ Cl }^{ - } $ ions are free to move only in molten state or aqueous solution. Hence, they show electrical conductivity in molten state.

Brine is a solution of salt ( usually sodium chloride ) in water.

Molten sodium chloride contains sodium ions and chloride ions which are free to move. 

Crude common salt contains impurities such as $ CaSO _{ 4 },   CaCl _{ 2 } ,   MgCl _{ 2} $. Hence it is deliquescent (hygroscopic).

Current is the rate of flow of charge. NaCl is an ionic solid. An ionic solid consists of a lattice of ${ Na }^{ + }$ and ${ Cl }^{ - }$ ions in which these ions are fixed in their places. Solid NaCl does not contain any mobile charge carriers that can facilitate the flow of charge. But molten NaCl contains free mobile ions ${ Na }^{ + }$ and ${ Cl }^{ - }$ ions which allow the passage of current.