Question detail
What is the observation when aqueous copper(II) ions react with sodium hydroxide?
Try the question, check the answer, then read the explanation to understand the curriculum point.
At a glance
MCQ
Type
practice
Style
Topic
Reactions of ions in aqueous solution (A-level only)
Question
- A. A blue precipitate forms
- B. A green precipitate forms
- C. No precipitate forms
- D. A white precipitate forms
Answer
A blue precipitate forms
Explanation
The correct option is A blue precipitate forms. A blue precipitate forms is the best answer because it directly supports the AQA A-Level Chemistry objective to describe reactions of aqueous metal ions with sodium hydroxide. This reasoning is anchored to Aqueous ion tests (A-level only) in Reactions of ions in aqueous solution (A-level only), and it separates reactions 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.
Common mistake
Misidentifying Precipitate Colors
Students often incorrectly describe the color of the precipitate formed when aqueous metal ions react with sodium hydroxide, confusing different metal ions.
To accurately describe the color of the precipitate, remember the specific reactions: for example, when copper(II) ions react with sodium hydroxide, the formula is Cu²⁺ + 2OH⁻ → Cu(OH)₂ (s), which forms a blue precipitate. Always refer to the specific metal ion and its corresponding hydroxide color.
Related flashcards
Flashcard 1 of 5
Related practice questions
Question 1 of 5
Choose an answer, get feedback, then move sideways through the set.