2022 The p-Block Elements (Group 15 to 18)Group 16 Elements – Hydrides Medium Question 1 of 2 in Group 16 Elements – Hydrides

Given below are two statements: Statement I: The boiling points of the following hydrides of group 16 elements increases in the order- $H_2O<H_2S<H_2Se<H_2Te$ Statement II: The boiling points of these hydrides increase with increase in molar mass. In the light of the above statements, choose the most appropriate answer from the options given below:

A Statement I is incorrect but Statement II is correct
B Both Statement I and Statement II are correct
C Both Statement I and Statement II are incorrect
D Statement I is correct but Statement II is incorrect

The answer is C.

Solution

From $H_2S$ to $H_2Te$, boiling point increases with molar mass (van der Waals forces), but $H_2O$ has the highest boiling point due to hydrogen bonding. Correct order: $H_2S < H_2Se < H_2Te < H_2O$ So Statement I ($H_2O$ lowest) is incorrect, and Statement II (boiling points of all these hydrides increase with molar mass) is also incorrect because of the anomaly of water. So both statements are incorrect.

Concept boiling point trend of group 16 hydrides

Group 16 Elements – Hydrides in past papers

2 questions from this chapter have appeared across 2 exam years.