A unit of $BaC{l_2}$(fluorite structure) is made up of:
(A) four $B{a^{2 + }}$ions and four $C{l^ - }$ions
(B) four $B{a^{2 + }}$ions and eight $C{l^ - }$ions
(C) eight $B{a^{2 + }}$ions and four $C{l^ - }$ions
(D) four $B{a^{2 + }}$ions and six $C{l^ - }$ions

Hint: Crystalline barium chloride is an orthogonal crystal structure and dehydrate $BaC{l_2}$ has a monocyclic crystal structure. Barium chloride is used industrially in the purification process of brine solution.

Complete step by step solution:
(1) Barium chloride is an inorganic salt.
(2) It is made up of barium cations and chloride anions.
(3) It is a unit solid which is water soluble.
(4) The molecular weight of barium chloride is $BaC{l_2}.$
(5) The melting point is ${962^\circ }C.$
(6) The structure of barium sulphide is

(7) It is obtained into two steps.
Step-1: From the barium surface at high temperature.
$BaS{O_4} + 4C \to BaS + 4CO$
Step-2: From barium sulphide.
$BaS + 2HCl \to BaC{l_2} + {H_2}S$
(8) Aqueous solutions of barium chloride have neutral $pH$ values since they contain cation of strong base and anion of strong acid.

Note:
1. Do not forget to balance the chemical equation you write. Balanced chemical equations show the number of units of a compound used in the reaction.
2. Barium chloride is used in the purification of brine solutions that are used in carrying chlorine plants.