Question

The hydride with lowest acid strength among the following is

• A. \(\text{H}_{2}\text{Se}\)
• B. \(\text{H}_{2}\text{Te}\)
• C. \(\text{H}_{2}\text{O}\)
• D. \(\text{H}_{2}\text{S}\)

Hint:

Acidity of group 16 hydrides increases down the group as the E-H bond becomes weaker.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
Acid strength depends on how easily the E-H bond releases \(\text{H}^{+}\).

Step 2: Trend in the group
Down the group the atomic size grows, so the E-H bond becomes longer and weaker.
Acid strength order: \(\text{H}_{2}\text{O}<\text{H}_{2}\text{S}<\text{H}_{2}\text{Se}<\text{H}_{2}\text{Te}\).

Step 3: Conclusion
Oxygen is the smallest atom with the strongest O-H bond, so \(\text{H}_{2}\text{O}\) is the weakest acid.

Final Answer:
Water is the hydride with the lowest acid strength. \[ \boxed{\text{(C) }\text{H}_{2}\text{O}} \]