In a solution, turmeric becomes reddish-brown and red litmus turns blue. Which ion will be in excess?
Answer and explanation
Correct answer: Hydroxide ion
Reddish-brown turmeric and blue red litmus are both tests for a basic medium. In aqueous school-level chemistry, basicity is associated with an excess of hydroxide ions, OH⁻, over hydrogen ions. Therefore hydroxide ion is the best answer. Hydrogen ions would indicate acidity, whereas chloride and sulphate ions may occur in salts but do not by themselves determine the observed indicator changes. Hence option A is correct.
Frequently asked questions
What is the correct answer to this question?
Hydroxide ion
Why is this the correct answer?
Reddish-brown turmeric and blue red litmus are both tests for a basic medium. In aqueous school-level chemistry, basicity is associated with an excess of hydroxide ions, OH⁻, over hydrogen ions. Therefore hydroxide ion is the best answer. Hydrogen ions would indicate acidity, whereas chloride and sulphate ions may occur in salts but do not by themselves determine the observed indicator changes. Hence option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
