Question

The decreasing order of electrical conductivity of the following aqueous solutions is : 0.1 M Formic acid (A), 0.1 M Acetic acid (B) 0.1 M Benzoic acid (C)

• A. C > B > A
• B. A > B > C
• C. A > C > B
• D. C > A > B

Answer 1

The Correct Option is C

The problem requires us to arrange the given aqueous solutions of carboxylic acids in decreasing order of their electrical conductivity. Electrical conductivity in ionic solutions primarily depends on the degree of ionization of the acid in water. The higher the degree of ionization, the greater the conductivity.

Let's evaluate each acid:

1. Formic Acid (HCOOH): This is a relatively stronger acid compared to the other two given options. It ionizes more in solution, providing more ions and thus, has higher conductivity.
2. Acetic Acid (CH₃COOH): This is a weaker acid compared to formic acid and has less ionization, leading to lower conductivity.
3. Benzoic Acid (C₆H₅COOH): This has a large, non-polar benzene ring, making it even less ionized compared to acetic acid. Hence, it shows the least conductivity in an aqueous solution.

Therefore, the decreasing order of electrical conductivity of the given acids is:

• Formic Acid > Benzoic Acid > Acetic Acid

The correct option is: A > C > B

Here's how the options compare:

• A > B > C: Incorrect, as Benzoic acid has a higher conductivity than Acetic acid.
• C > B > A: Incorrect, as Formic acid is the strongest in conductivity.
• C > A > B: Incorrect, as Acetic acid is less conductive than Benzoic acid.
• A > C > B: Correct, as explained above.