Transition Metal color Changes

Question 1

What is the appearance of the solution for [Fe(H₂O)₆]³⁺?

Answer 1

Yellow solution

This is a characteristic color of iron(III) complexes in aqueous solution.

Question 2

What is the color of the solution for [Al(H₂O)₆]³⁺?

Answer 2

colourless solution

Aluminum complexes are typically colorless in aqueous solution.

Question 3

What color does [Cr(H₂O)₆]³⁺ produce in solution?

Answer 3

pale green solution

Chromium(III) in aqueous solution shows a pale green color.

Question 4

What is the color of the solution for [Fe(H₂O)₆]²⁺?

Answer 4

yellow solution

Iron(II) complexes can display a yellow hue in solution.

Question 5

What color does [Co(H₂O)₆]²⁺ produce in solution?

Answer 5

pink solution

Cobalt(II) complexes are known for their pink coloration.

Question 6

What color is associated with [Cu(H₂O)₆]²⁺?

Answer 6

blue solution

Copper(II) solutions are typically blue due to its coordination complex.

Question 7

What happens when [Fe(H₂O)₆]²⁺ reacts with NaOH?

Answer 7

dirty green ppt

This indicates the formation of iron(II) hydroxide precipitate.

Question 8

What is the precipitate formed with [Al(H₂O)₆]³⁺ and NaOH?

Answer 8

white ppt

Aluminum hydroxide precipitate is white when formed.

Question 9

What precipitate is formed when [Cr(H₂O)₆]³⁺ reacts with NaOH?

Answer 9

pale green ppt

Chromium(III) hydroxide precipitate appears pale green.

Question 10

What is the precipitate for [Fe(H₂O)₆]³⁺ with NaOH?

Answer 10

brown ppt

This indicates the formation of iron(III) hydroxide.

Question 11

What color precipitate does [Co(H₂O)₆]²⁺ form with NaOH?

Answer 11

blue ppt

Cobalt(II) hydroxide can form a blue precipitate.

Question 12

What is the precipitate formed from [Cu(H₂O)₆]²⁺ with NaOH?

Answer 12

pale blue ppt

Copper(II) hydroxide precipitate is pale blue.

Question 13

What happens to the color of the solution when [Fe(H₂O)₆]²⁺ stands?

Answer 13

straw solution (darkens on standing)

Iron(II) solutions can oxidize to iron(III), changing color.

Question 14

What is the color of the solution when [Cu(H₂O)₆]²⁺ is formed?

Answer 14

blue solution

This indicates a concentrated copper(II) solution.

Question 15

What color precipitate is formed when [Fe(H₂O)₆]³⁺ reacts with Na₂CO₃?

Answer 15

green ppt (carbonate)

Iron(III) carbonate precipitates often show a green color.

Question 16

What precipitate is formed with [Al(H₂O)₆]³⁺ and Na₂CO₃?

Answer 16

white ppt (hydroxide)

Aluminum carbonate can lead to a white precipitate.

Question 17

What color precipitate does [Cr(H₂O)₆]³⁺ form with Na₂CO₃?

Answer 17

pale green ppt (hydroxide)

Chromium(III) carbonate can precipitate as pale green.

Question 18

What color is associated with the precipitate formed from [Co(H₂O)₆]²⁺ with Na₂CO₃?

Answer 18

pink ppt (carbonate)

Cobalt(II) carbonate typically appears pink.

Question 19

What color precipitate does [Cu(H₂O)₆]²⁺ form with Na₂CO₃?

Answer 19

green/blue ppt (carbonate)

Copper(II) carbonate can show greenish-blue tones.