Sodium chloride, chloride sodium, sodium salt of hydrochloric acid – all this different names of the same chemical – NaCl which is the main component of table salt.
Instruction
1. Sodium chloride in pure form represents colourless crystals, but in the presence of impurity can accept a yellow, pink, violet, blue or gray shade. In the nature of NaCl meets in the form of mineral of halite of which household table salt is made. The huge amount of chloride sodium is dissolved also in sea water.
2. Halite is the transparent, colourless mineral with glass gloss having a face-centered cubic lattice (GCK-lattice). It contains 60.66% of chlorine and 39.34% of sodium.
3. Temperature of melting of NaCl – 800.8˚C, boilings - 1465˚C. It is moderately soluble in water, and the solubility poorly depends on heating, but is reduced in the presence of chlorides of other metals, sodium hydroxide, chlorohydrogen significantly. Table salt is dissolved in liquid ammonia and enters exchange reactions with other substances. Clean NaCl is not hygroscopic, but in the presence of impurity (Ca(2+), Mg(2+), SO4(2-)) grows damp on air.
4. In the molecule NaCl ionic communication between Na and Cl, as sodium and chlorine – atoms with the big difference of elektrootritsatelnost (> 1.7). The general electronic couple in this case completely passes to atom with bigger electronegativity – to chlorine. The positive ion of Na+ sodium, a negative ion of Cl-chlorine is as a result formed, and between them there is an electrostatic attraction – ionic communication. It can be considered as a limit case of a covalent polar bond.
5. In the course of formation of ionic communication, atoms pass into steadier state. Electronic configurations of ions complete. But ionic communication differs from covalent as electrostatic forces disperse from an ion extensively. It caused not orientation and also not saturability of ionic communication.
6. Each cation of Na + in a crystal lattice of table salt is surrounded with six Cl-anions, and each chloride ion is surrounded, respectively, with six ions of sodium. Thus, all atoms are located serially in tops and the centers of sides of a simple cubic lattice.