Q20 / 75 · JEE Main 2026 (05 April Shift 1) · Chemistry
Given below are two statements:
Statement I: Sodium dichromate and potassium dichromate are classified as primary standards in titrimetric analysis.
Statement II: Phenolphthalein is a weak base, therefore it dissociates in acidic medium.
In the light of the above statements, choose the correct answer from the options given below
Statement I: Sodium dichromate and potassium dichromate are classified as primary standards in titrimetric analysis.
Statement II: Phenolphthalein is a weak base, therefore it dissociates in acidic medium.
In the light of the above statements, choose the correct answer from the options given below
- ABoth Statement I and Statement II are true
- Correct answerBBoth Statement I and Statement II are false
- CStatement I is true but Statement II is false
- DStatement I is false but Statement II is true
Solution
Statement I is false because sodium dichromate is deliquescent (absorbs moisture from the atmosphere) and cannot be weighed accurately, so it is not used as a primary standard. Potassium dichromate, however, is a primary standard.
Statement II is false because phenolphthalein is a weak organic acid, not a weak base. It remains largely undissociated in an acidic medium (colorless) and dissociates in a basic medium to give a pink color.
Therefore, both Statement I and Statement II are false.
Answer: Both Statement I and Statement II are false
Statement II is false because phenolphthalein is a weak organic acid, not a weak base. It remains largely undissociated in an acidic medium (colorless) and dissociates in a basic medium to give a pink color.
Therefore, both Statement I and Statement II are false.
Answer: Both Statement I and Statement II are false
Hence, the correct answer is option: 'B'.