A2 Chemistry - Iron chemistry

Describe and explain what would happen if solution A were allowed to stand in contact with air. Solution A is [Fe(H2O)6]^2+

To [Fe(H2O)6]^2+ and [Fe(H2O)6]^3+, aqueous ammonia is added dropwise. If excess ammona were used, would any differences (if any) be observed?

Thanks.

Reply 1

charco

Study Forum Helper

18

brown colour forms at the surface due to Iron II being oxidised to iron III

[Fe(H2O)6]^2+ aqueous ammonia is added dropwise --> green gelatinous ppt
[Fe(H2O)6]^3+, aqueous ammonia is added dropwise ---> brown gelatinous ppt

no further change on adding excess NH3

Reply 2

Christophicus

OP

18

charco

brown colour forms at the surface due to Iron II being oxidised to iron III

[Fe(H2O)6]^2+ aqueous ammonia is added dropwise --> green gelatinous ppt
[Fe(H2O)6]^3+, aqueous ammonia is added dropwise ---> brown gelatinous ppt

no further change on adding excess NH3

Out of interest, are you a student? Or have you done a chemistry degree or something?