Phosphorous pentachloride is used in the industrial preparation of many organic phosphorous compounds. equation i shows its preparation from pcl3 and cl2: (i) pcl3 (l) + cl2(g)  pcl5(s) use equation ii and iii to calculate ∆hrxs of equation i: (ii) p4 (s) + 6 cl2 (g)  4 pcl3 (l) ∆h = 1280 kj (iii) p4 (s) + 10 cl2 (g)  4 pcl5 (s) ∆h = 1774 kj

The enthalpy of the reaction is -123.5 kJ.

Explanation:

..(1)

..(2)

...(3)

(2) - (1)

Dividing equation by 4 we get (3)

...(3)

The enthalpy of the reaction is -123.5 kJ.

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.