A solution turns red litmus blue and gives pink colour with phenolphthalein. What is the nature of the solution?
Answer and explanation
Correct answer: Basic
Red litmus turning blue is evidence of a basic medium. Phenolphthalein provides a second confirming observation because it becomes pink in a basic solution and remains colourless in acidic or neutral conditions. Since both tests point to the same chemical nature, the solution is basic and option C is correct. A neutral solution would not normally change red litmus or produce the pink phenolphthalein colour, while the last option is contradictory and unsupported.
Frequently asked questions
What is the correct answer to this question?
Basic
Why is this the correct answer?
Red litmus turning blue is evidence of a basic medium. Phenolphthalein provides a second confirming observation because it becomes pink in a basic solution and remains colourless in acidic or neutral conditions. Since both tests point to the same chemical nature, the solution is basic and option C is correct. A neutral solution would not normally change red litmus or produce the pink phenolphthalein colour, while the last option is contradictory and unsupported.
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.
