What is the result of adding excess ammonia to a solution containing aqueous zinc ions? Describe the observation and the final complex formed.

When excess ammonia is added to a solution containing aqueous zinc ions (Zn^2+), a colorless solution forms due to the formation of the complex ion [Zn(NH3)4]^2+. The observation is that the solution remains colorless. This answer is anchored to Aqueous ion tests (A-level only).

When excess ammonia is added to a solution containing aqueous zinc ions (Zn^2+), a colorless solution forms due to the formation of the complex ion [Zn(NH3)4]^2+. The observation is that the solution remains colorless. is the best answer because it directly supports the AQA A-Level Chemistry objective to describe reactions of aqueous metal ions with ammonia. This reasoning is anchored to Aqueous ion tests (A-level only) in Reactions of ions in aqueous solution (A-level only), and it separates ammonia from similar A-Level ideas rather than relying on a vague recall statement. Other options are weaker if they use the wrong evidence, calculation, mechanism, observation, unit, or conclusion for this subtopic.