Question

Why is the boiling point of `H_2Te` higher than the boiling point of `H_2S`?

Answer 1

Well, clearly the degree of intermolecular force is LESS in hydrogen sulfide, than in hydrogen telluride....

Explanation:

There is some little degree of hydrogen-bonding in `H_2S`, tho much less so than in `H_2O`....and hence water is a room temperature liquid.

On the other hand, while the degree of hydrogen-bonding in `H_2Te` is less than in `H_2S`, and MUCH less than in `H_2O`, hydrogen telluride is a many electron molecule, the which should have greater opportunity for dispersion forces....

And as chemists, as physical scientists, we should interrogate actual data, and list the normal boiling points, so that we know that we are barking up the right tree...

`H_2O: 100` `""^@C;`

`H_2S: -60` `""^@C;`

`H_2Se: -41.25` `""^@C;`

`H_2Te: -2.25` `""^@C.`

I think I have written before here that while hydrogen sulfide smells pretty bad, hydrogen selenide and hydrogen telluride smells like a week-old dead dog. `H_2Se` and `H_2Te` are also very poisonous, more so than `HC-=N`...