JEE Main 2025 Chemistry question
Compounds that should not be used as primary standards in titrimetric analysis are : A. B. Oxalic acid C. NaOH D. E. Sodium tetraborate Choose the most appropriate answer from the options given below:
Answer: (2)
Solution
NaOH, FeSO4ยท6H2O, Na2Cr2O7 are not suitable as primary standards due to hygroscopicity/instability