A orange-brown precipitate forms when sodium hydroxide is added. Which ion is present?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $24.99Unlock all

Study for the IGCSE Edexcel Chemistry Test. Access flashcards and multiple choice questions with hints and explanations. Get ready for your exam!

Multiple Choice

A orange-brown precipitate forms when sodium hydroxide is added. Which ion is present?

Explanation:
When you add sodium hydroxide, hydroxide ions react with metal ions to form metal hydroxides. If the hydroxide is insoluble, it appears as a precipitate, and its color helps identify the ion. Iron(III) hydroxide, Fe(OH)3, is a brownish-orange solid, so an orange-brown precipitate points to Fe3+. Aluminium would give white Al(OH)3 (and in excess base dissolves to a colorless solution), copper(II) gives a blue precipitate of Cu(OH)2, and calcium gives a white Ca(OH)2 precipitate. Therefore, the ion present is Fe3+.

When you add sodium hydroxide, hydroxide ions react with metal ions to form metal hydroxides. If the hydroxide is insoluble, it appears as a precipitate, and its color helps identify the ion. Iron(III) hydroxide, Fe(OH)3, is a brownish-orange solid, so an orange-brown precipitate points to Fe3+. Aluminium would give white Al(OH)3 (and in excess base dissolves to a colorless solution), copper(II) gives a blue precipitate of Cu(OH)2, and calcium gives a white Ca(OH)2 precipitate. Therefore, the ion present is Fe3+.

More Multiple Choice Questions
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy