unit 1/2 help

[jack_chay]

Intermolecular forces are related to the boiling points/melting points/solubility etc.. (eg a low boiling point is due to weak intermolcular forces not intramolecular)

What is intramolecular forces related to then?
How do you know whether the compound will have weak or strong intramolecular forces?

thanks in advance

[jgoudie]

Intramolecular forces are those within a molecule, aka the covalent bonds.  These really don't play much of a part in the unit 1/2 in terms of a molecules properties.

When you get into unit 3/4 you will learn about activation energy and this is where these forces come into play (in a small way).  When intramolecular forces are broken the molecule completely breaks apart, this happens during a chemical reaction.

Below is a video on the various intermolecular forces. 
http://www.youtube.com/watch?v=U3ApPGqsxbc

Intermolecular forces are related to the boiling points/melting points/solubility etc.. (eg a low boiling point is due to weak intermolcular forces not intramolecular)

What is intramolecular forces related to then?
How do you know whether the compound will have weak or strong intramolecular forces?

thanks in advance

[PB]

Lets look at what the terms mean first.
Intermolecular forces are the weak bonds between molecules, whereas inTRAmolecular forces are the relatively stronger bonds inside molecules.
 So you are right for the first part, intermolecular forces dictates the boiling points/melting points/ solubility etc. For example, the reason why water is a liquid and not a gas at room temperature is because the H2O molecules all exert hydrogen bonds and dispersion forces (two types of intermolecular forces) on each other, holding everything together so that they don't go flying off everywhere, like gases.

Intramolecular forces hold a singular molecule together. Going back to water - the intramolecular forces are the covalent bonds between oxygen and hydrogen atoms. There are three main types of intramolecular forces - covalent, ionic and metallic, and all are usually MUCH stronger than intermolecular forces. If not you would be breaking down water into oxygen and hydrogen gas everytime the temperature heats up! (explosions everywhere...)

As jgoudie said, the strength of intramolecular bonds are associated with something called "activation energy" which I do not believe is discussed in much detail in Units 1+2.

I hope that helps btw, I have also answered your physics questions.

[PB]

One of Sulfuric Acid's most prominent characteristics is its highly dehydrative properties. Meaning that it will strip away any water from a compound if given the chance.
So it really narrows the options down to A+B due to both of them containing sulfuric acid (HCl does nothing in this case really...). And finally, it has to be B because you don't want to dry the CO2 and then wet it again.