Question

A more reactive halogen will displace a less reactive halogen from a solution of its salt. Which equation is correct?

a) bromine + potassium iodide → potassium bromide + iodine
b) chlorine + potassium iodide → potassium iodine + chlorine
c) chlorine + potassium bromide → bromine chloride + potassium
d) chlorine + potassium bromide → potassium chloride + bromine

Answer 1

The correct equation for a halogen displacement reaction, as per the reactivity series of halogens, is option d), where chlorine displaces bromine from potassium bromide to form potassium chloride and elemental bromine. The correct option is d.

Step-by-step explanation:

The correct equation for a halogen displacement reaction, where a more reactive halogen displaces a less reactive halogen from a solution of its salt, is given as:

d) chlorine + potassium bromide → potassium chloride + bromine

Chlorine, being above bromine in the halogen group (group 17) of the periodic table, is more reactive and can thus displace bromine from a compound like potassium bromide. The general form of this type of reaction can be represented by:

Cl₂ (g) + 2NaBr (aq) → 2NaCl (aq) + Br₂ (l)

Consistent with the reactivity trend of halogens, chlorine, being more reactive than bromine, replaces the bromide ions present in the compound to form sodium chloride and elemental bromine. The correct option is d.