Question:easy

Which of the following compounds is most acidic in nature?

Show Hint

Acidity of group 16 hydrides rises down the group because the H-E bond gets weaker as E gets larger.
Updated On: Oct 1, 2026
  • \(\text{H}_2\text{O}\)
  • \(\text{H}_2\text{S}\)
  • \(\text{H}_2\text{Se}\)
  • \(\text{H}_2\text{Te}\)
Show Solution

The Correct Option is D

Solution and Explanation

Step 1: Think in terms of the conjugate base:
When $\text{H}_2\text{E}$ loses a proton it forms $\text{HE}^-$. The larger the atom E, the more the negative charge spreads over a big volume, so the ion is more stable.

Step 2: Rank the conjugate bases:
Stability of $\text{HE}^-$ rises as $\text{OH}^- < \text{SH}^- < \text{SeH}^- < \text{TeH}^-$. A more stable conjugate base means a stronger parent acid.

Step 3: Conclude:
$\text{H}_2\text{Te}$ has the most stable conjugate base and the weakest H-Te bond, so it is the most acidic. Its dissociation constant is the largest of the four.

Final Answer:
Because the H-Te bond is the weakest, $\text{H}_2\text{Te}$ is the strongest acid. \[ \boxed{\text{(D) }\text{H}_2\text{Te}} \]
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