Question

Statement I : Sodium and Potassium dichromate are used as a primary standard in redox titrations.
Statement II : Phenolphthalein is weakly basic in nature hence it dissociates in acidic medium.

• A. Both Statement I and Statement II are correct
• B. Statement I is correct but Statement II is incorrect.
• C. Statement I is incorrect but Statement II is correct.
• D. Both Statement I and Statement II are incorrect

Answer 1

The Correct Option is D

Concept:
Primary standards must be stable and non-hygroscopic. Indicators like phenolphthalein behave as weak acids, not bases. Step 1: Analyze Statement I. \[ Na_2Cr_2O_7 \text{ is hygroscopic, hence not used as primary standard} \] Statement I is incorrect. Step 2: Analyze Statement II. Phenolphthalein is a weak acid, not a base. Statement II is incorrect. Step 3: Final answer. \[ \boxed{\text{Both statements are incorrect}} \]