JAMB Chemistry 1980 Question 17

Question 17

Halogens

Chlorine, bromine and iodine resemble each other in that all

A.dissolve in alkalis
B.react violently with hydrogen without heating
C.displace each other from solutions of their salts
D.are gases
E.are liquids.

Show the answer and explanation

Answer: A (dissolve in alkalis)

Explanation

All three halogens react with alkali solutions (e.g. Cl₂ + 2NaOH → NaCl + NaOCl + H₂O). Iodine cannot displace the others, only chlorine reacts violently with hydrogen, and they are a gas, a liquid and a solid.