Question

What is the colour of the product when ammonia reacts with a solution of $Cu^{2+}$?

• A. Orange
• B. Green
• C. Deep blue
• D. Yellow

Answer 1

Answer: (C)

Deep blue

Answer 2

When ammonia (NH3) reacts with a solution of copper(II) ions (Cu$_2^+$), it forms a complex ion, specifically [Cu(NH3)4]$_2^+$, which is characterized by a deep blue color. This deep blue solution is a result of the formation of the copper-ammonia complex.
The correct answer is Deep blue.