Question

An aqueous solution ‘X’ turns Phenolphthalein Solution pink. On adding the aqueous Solution ‘Y’ to ‘X’ the pink colour disappears. Which of the following statements is true for Solution ‘X’ and ‘Y’?

A. ‘X’ is strongly basic, and ‘Y’ is a weak base.
B. ‘X’ is strongly acidic, and ‘Y’ is a weak acid.
C. ‘X’ is a basic solution and ‘Y’ is an acidic solution.
D. ‘X’ is an acidic solution and ‘Y’ is a basic solution.


Which option is correct​

Answer 1

Answer:

option C.

Explanation:

Phenolphthalein solution turns pink in basic solutions. Hence, solution A lies in the pH range of above 7. On adding solution B the pink colour disappears hence it has a pH less than 7, then the pH of the final solution will decrease.

Answer 2

The following statement is true for Solution ‘X’ and ‘Y’ - C. ‘X’ is a basic solution and ‘Y’ is an acidic solution.

Phenolphthalein is an indicator used for determining acidic and basic solutions. It is colourless and turns light pink in alkaline solution.

As mentioned, aqueous solution X turns phenolphthalein solution pink. Hence, it is basic.

Also, the addition of Y to X makes the pink colour disappear. Hence, it can be confirmed that Y is an acidic solution.