Question

The primary standard used to standardize acetic perchloric acid is

• A. Benzoic acid
• B. Potassium hydrogen phthalate
• C. Oxalic acid
• D. Sodium carbonate

Hint:

Potassium hydrogen phthalate (KHP) is widely used as a primary standard for acid-base titrations due to its stability and known purity.

Answer 1

The Correct Option is B

Step 1: Understanding acid-base titration standards.
In acid-base titrations, it is important to use a primary standard to determine the exact concentration of the titrant. Potassium hydrogen phthalate is commonly used for this purpose in the standardization of acetic perchloric acid.
Step 2: Analyzing the options.

• (A) Benzoic acid: Incorrect. Benzoic acid is not commonly used for standardizing acetic perchloric acid.
• (B) Potassium hydrogen phthalate: Correct. Potassium hydrogen phthalate is a well-known primary standard used to standardize solutions of strong acids like acetic perchloric acid.
• (C) Oxalic acid: Incorrect. Oxalic acid is used in certain titrations but is not commonly used for standardizing acetic perchloric acid.
• (D) Sodium carbonate: Incorrect. Sodium carbonate is used as a primary standard for some bases but not typically for standardizing acetic perchloric acid.

Step 3: Conclusion.
Potassium hydrogen phthalate is the primary standard used for the accurate standardization of acetic perchloric acid. Final Answer:} Potassium hydrogen phthalate.