Chemistry question dipole

Hi, please could I have help on this question? I don’t know how to work out which one has temporary id-id forces?
Here is the question: https://app.gemoo.com/share/image-annotation/584502036535025664?codeId=v6ggx8gGQboXa&origin=imageurlgenerator

Thanks!

Hi, please could I have help on this question? I don’t know how to work out which one has temporary id-id forces?
Here is the question: https://app.gemoo.com/share/image-annotation/584502036535025664?codeId=v6ggx8gGQboXa&origin=imageurlgenerator

Thanks!

Temporary id-id forces are a synonym of van der Waals (London) forces. This means you are looking for a compound in which there are no hydrogen bonds and no permanent dipole-dipole interactions.

Both O2 and C4H10 have no permanent dipole-dipole forces or hydrogen bonds (since O2 doesn’t consist of atoms with differing electronegativities and hydrocarbons are nonpolar, as the C-H electronegativity difference is small), but what do you notice about the state symbols for each option?

In butane it is changing from liquid to solid and in oxygen, solid to liquid? How could i work it out from here? Thanks!

If something is going from liquid to solid (and vice versa), are intermolecular forces of any kind becoming overcome?

Think about what the word overcome implies.

Ohh so would it be oxygen because the intermolecular forces are being weakened therefore there is a change in state from solid to liquid? Thanks!

Precisely.

Well done on reaching what I can only presume is the right answer to yet another awful mcq you’ve managed to stumble across.

Temporary id-id forces are a synonym of van der Waals (London) forces. This means you are looking for a compound in which there are no hydrogen bonds and no permanent dipole-dipole interactions.

Both O2 and C4H10 have no permanent dipole-dipole forces or hydrogen bonds (since O2 doesn’t consist of atoms with differing electronegativities and hydrocarbons are nonpolar, as the C-H electronegativity difference is small), but what do you notice about the state symbols for each option?

vdW is id-id, pd-id and pd-pd.

Some exam boards suggested that vdW was only id-id, but they have now seen the error of their ways.