C4.1.3

Question 1

What can halogens react with in solution?

Answer 1

• they can react with halides
• halides are compounds containing a Group 7 and another element (usually a hydrogen/metal)
  For eg. Cl2(g) + 2NsBr(aq) —> 2NaCl(aq) + Br2(aq)

Question 2

Why is it called a displacement reaction?

Answer 2

• a more reactive halogen will displace a less reactive halide from solutions of its salts
  (It’s safer to use aqueous solutions in school rather than pure elements)

Question 3

Combine these two equations:
Cl2 + 2e- —> 2Cl-
2Br —> Br2 + 2e-

Answer 3

Cl2 + 2Br —> 2Cl- + Br2