Question

The correct order of the boiling points of the compounds is

• A. CH$_4$>SiH$_4$>SnH$_4$>GeH$_4$
• B. SiH$_4$>CH$_4$>GeH$_4$>SnH$_4$
• C. SnH$_4$>GeH$_4$>CH$_4$>SiH$_4$
• D. SnH$_4$>GeH$_4$>SiH$_4$>CH$_4$

Hint:

Boiling points of Group 14 hydrides increase down the group due to stronger dispersion forces.

Answer 1

The Correct Option is D

Step 1: Trend in boiling points.
For hydrides of Group 14 elements, boiling point increases down the group because molecular mass increases. Higher molecular mass increases van der Waals (London dispersion) forces, raising boiling points.
Step 2: Applying the trend.
Order of molecular mass is: SnH$_4$>GeH$_4$>SiH$_4$>CH$_4$. Hence boiling points follow the same order.
Step 3: Conclusion.
The correct increasing order of boiling points is SnH$_4$>GeH$_4$>SiH$_4$>CH$_4$.