Haloalkanes (1 Viewer)

[lilchezza]

okiez, I guess this may seem pretty simple, but just started on these thingo's and my teacher was away......and we got a sub not trained in chem :mad1: .

2. Haloalkanes have higher densities and higher melting and boiling points than their corresponding alkanes. Explain.

I'm guessing that it would just be something to do with longer chain, more elements therefore more bonds to break.............

 

[Riviet]

Not sure about the higher density, but haloalkanes do have a longer chain, meaning more dispersion forces and bonds to break, therefore requiring more energy/heat to overcome them.

 

[insert-username]

2. Haloalkanes have higher densities and higher melting and boiling points than their corresponding alkanes. Explain.

I believe the increased density is to do with haloalkanes having halogen atoms replacing hydrogen atoms in their structure. Halogen atoms are much heavier than hydrogen atoms, and this contributes to the substance being denser.


I_F

 

[rama_v]

Haloalkanes and corresponding alkanes are exactly the same length (in terms of number of carbon atoms) so that would not answer the question. However, haloalkanes have stronger intermolecular forces due to the high electronegativity of the halogen present (e.g. Cl or F), which sets up dipole interactions between the molecules. This would increase boiling and melting points.