Predicting missing boiling point in the following series of compounds:

[Hooke's Law]

Homework Statement

a) CH4 -164 C , SiH4 -112 C, GeH4, -90 C, SnH4, ? C.

b) H2O ? C, H2S -61 C, H2Se -41 C, H2Te -2 C

The Attempt at a Solution

a)This was an assignment and the right answer was T= -75 C. I did a graph starting from CH4 to SnH4 and I know this because its going down a group from the periodic table. But I don't know how to get the right answer ( -75 C)

b) Right answer : -71 C . Similarly, I did a graph from H2O to H2Te and didnt know how to get the right answer.

Thanks

 

[Borek]

Have you tried to extend the graph and read from it?