Transition Metals

Question	Answer
Cu^2+ in solution	[Cu(H2O)6]^2+ / Pale Blue
Mn^2+ in solution	[Mn(H2O)6]^2+ / Very Pale Pink
Fe^2+ in solution	[Fe(H2O)6]^2+ / Pale Green
Fe^3+ in solution	[Fe(H2O)6]^3+ / Pale Yellow
Cr^3+ in solution	[Cr(H2O)6]^3+ / Pale Purple or [Cr(H2O)5(SO4)]^+ / Green
Cu^2+ with OH^-	Cu(OH)2 / Pale Blue ppt.
Cu(OH)2 left standing in air	No change
Mn^2+ with OH^-	Mn(OH)2 / Light Brown ppt.
Mn^2+ left standing in air	Oxidises to Mn(OH)3 Darkens to Brown ppt.
Fe^2+ with OH^-	Fe(OH)2 / Green ppt.
Fe(OH)2 left standing in air	Oxidises to Fe(OH)3 Darkens to Orange-Brown ppt.
Fe^3+ with OH^-	Fe(OH)3 / Orange-Brown ppt.
Fe(OH)3 left standing in air	No change
Cr^3+ with OH^-	Cr(OH)3 / Grey-Green ppt.
Cr(OH)3 left standing in air	No change
What ion reacts with excess OH^-	Cr^3+
Cr^3+ in excess OH^-	[Cr(OH)6]^3- Dark Green solution (all other TM ions are insoluble)
Cu^2+ with NH3	Cu(OH)2 Pale Blue ppt.
Mn^2+ with NH3	Mn(OH)2 Brown ppt.
Fe^2+ with NH3	Fe(OH)2 Green ppt.
Fe^3+ with NH3	Fe(OH)3 Orange-Brown ppt.
Cr^3+ with NH3	Cr(OH)3 Grey-Green ppt.
What two ions react in excess NH3?	Cu^2+ and Cr^3+
Cu^2+ with excess NH3	[Cu(NH3)4(H2O)2]^2+ Deep Blue solution
Cr^3+ in excess NH3	[Cr(NH3)6]^3+ Purple solution
What ion reacts reacts with conc. HCl	Cu^2+
Cu^2+ with conc. HCl	[CuCl4]^2- Yellow solution
What colour is MnO4^2- in solution?	Deep Purple
What colour is Cr2O7^2- in solution?	Orange
What colour is CuI ppt.?	White
What colour is I2 with starch?	Blue/Black

Resource summary

	Created by Lewis Tonge over 6 years ago