Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :
- Both Statement I and Statement II are true
- Both Statement I and Statement II are false
- Statement I is true but Statement II is false
- Statement I is false but Statement II is true
Answer
(2) Both Statement I and Statement II are false
Solution
Statement I: A primary standard must be obtainable pure and must not absorb moisture. As per NCERT, sodium dichromate is hygroscopic (and more soluble), so it is not used as a primary standard; only potassium dichromate is a primary standard in volumetric analysis. ⇒ Statement I is false.
Statement II: Phenolphthalein is a weak ACID (HPh). It dissociates (ionises) in basic medium, giving the pink Ph- ion; in acidic medium its ionisation is suppressed and it stays colourless. ⇒ Statement II is false.
∴ Both statements are false.
Answer: (2)