Question

Which of the following orders of acid strength is correct:

• A. RCOOH > ROH > HOH > HC ≡ CH
• B. RCOOH > HOH > ROH > HC ≡ CH
• C. RCOOH > HOH > HC ≡ CH > ROH
• D. RCOOH > HC ≡ CH > HOH > ROH

Answer 1

Answer: (B)

RCOOH > HOH > ROH > HC ≡ CH

Answer 2

Here's the rationale behind this order:
1. Carboxylic acids (RCOOH) are strong acids because they can donate a proton (H+) readily due to the presence of the carboxyl group (COOH). They have a dissociable hydrogen ion (H+), making them stronger acids than the other compounds listed.
2. Water (HOH) is also a strong acid but not as strong as carboxylic acids. Water can act as an acid by donating a proton (H+) to another molecule or ion, but it is weaker than carboxylic acids in this regard.
3. Alcohols (ROH) are weaker acids than both carboxylic acids and water. While they can donate a proton, it's less likely to occur compared to carboxylic acids and water.
4. Alkynes (HC ≡ CH) are the weakest acids among the listed compounds. They are not acidic under normal conditions and do not readily donate protons.

So, the correct order is (B): RCOOH > HOH > ROH > HC ≡ CH.