Question

Which boiling point is lower an why?
The boiling point of CH4 is lower than the boiling point of SiH4, whereas the boiling point of NH3 is higher than the boiling point of PH3. The lower boiling point of CH4 compared to SiH4
1 is expected because of the stronger induced dipole forces in CH4.
2 cannot be explained.
3 is expected because of its lower molecular weight.
4 is expected because of the stronger dipole forces in SiH4.
5 is expected because of the hydrogen bonding in SiH4.

Answer 1

Answer:4

Explanation:

If we carefully observe the electronegativity of the elements in question

P-2.19

N-3.04

C-2.55

Si-1.9

H-2.2

SiH4 is definitely more polar than CH4 hence greater dipole forces of a higher boiling point. NH3 is more polar than PH3 hence NH3 has greater dipole forces and a higher boiling point. Electronegative differences influences the polarity of a bond. The greater the electro negativity difference between bonding atoms, the greater the dipole forces and the greater the boiling point.

Answer 2

Answer:

4.

Explanation:

Is expected because of the stronger dipole forces in SiH4.