chemistry 1/2 questions thread

[alchemy]

Hi guys! Does anybody have worksheets on the mole and mole calculations or know of any good online quizzes, resources etc?? i have a test coming up and I'm looking for some extra revision.

Hey jess, you could try this for practice questions: http://www.sciencegeek.net/Chemistry/taters/directory.shtml. They're all relatively easy btw.
And click on the learning outcome links on this page for theory behind it all: http://www.chemguideforcie.co.uk/sect1menu.html#top

[IndefatigableLover]

Hey jess, you could try this for practice questions: http://www.sciencegeek.net/Chemistry/taters/directory.shtml. They're all relatively easy btw.
And click on the learning outcome links on this page for theory behind it all: http://www.chemguideforcie.co.uk/sect1menu.html#top[/b]

ChemGuide is literally something you can't live without when it comes to VCE Chemistry LOL
It's like your second textbook (only that it's free )

[jessica666]

Hey jess, you could try this for practice questions: http://www.sciencegeek.net/Chemistry/taters/directory.shtml. They're all relatively easy btw.
And click on the learning outcome links on this page for theory behind it all: http://www.chemguideforcie.co.uk/sect1menu.html#top

thanks so much!

[jessica666]

ChemGuide is literally something you can't live without when it comes to VCE Chemistry LOL
It's like your second textbook (only that it's free )

thanks heaps! didn't know about that!

[MNM101]

Just wondering if an element has low melting temperature does that mean they have a weak force of attraction between the particles that make up the substance?

[IndefatigableLover]

Just wondering if an element has low melting temperature does that mean they have a weak force of attraction between the particles that make up the substance?

Generally associated with low melting temperatures are gases which have a weak force of attraction between the particles that make up the substance. It goes the opposite way as well where if the force of attraction between particles that make up the substance is strong then it's more likely to be a solid. So in short yes you are right MNM101

[MNM101]

Generally associated with low melting temperatures are gases which have a weak force of attraction between the particles that make up the substance. It goes the opposite way as well where if the force of attraction between particles that make up the substance is strong then it's more likely to be a solid. So in short yes you are right MNM101

Thanks!!

[rhinwarr]

Note that it's the intermolecular forces (between molecules) that determine the melting point NOT the intramolecular forces (within a molecule).

[jessica666]

What's the difference between covalent network lattices and covalent layer lattices??

[Einstein]

whats everyone upto in 1/2 chem? we're upto organic chem, nearly done

[alchemy]

What's the difference between covalent network lattices and covalent layer lattices??

Covalent network lattices  consist entirely of very strong carbon-carbon covalent bonds all linked to one another in three dimensions. Hence, a material that consists of a covalent network lattice structure (e.g. diamond) has a very high melting point and doesn't conduct electricity because there are no free moving electrons. It is insoluble in water and organic solvents because no attractions can possibly occur between carbon atoms of the covalent network lattice and solvent molecules.

Covalent layer lattices consist of sheets (layers) of carbon atoms bound together as well, but there is a gap between each of the layers. This characteristic makes a material, such as graphite, have a soft/greasy feel. Graphite has one delocalised electron per carbon atom, allowing it to conduct electricity in 2-dimentions (within sheets, BUT not between them). It has a high melting point as a large amount of energy is required to break the strong covalent bonds between carbon atoms. Another interesting fact about covalent layer lattices is that they have a lower density in comparison to covalent network lattices because of the space in between the sheets.

whats everyone upto in 1/2 chem? we're upto organic chem, nearly done

Almost finished organic chem. Really looking forward to getting Unit 1 over and done with!

[ronniecoollike]

Hi everyone, we are doing a summary report about metals, ionic compounds and convalent molecules. Why aren't metals soluble in water? Is it because their bonding is too strong? And why do some ionic substances dissolve in water when others dont? Is it because some have stronger bonding? (I'm not the best at chemistry and I can't find anything in the text book.)

[Einstein]

i think its because H20 (water) is a polar substance and the others may be non-polar, where the 'like dissolves like' rule comes into play.

I think ionic compounds when put in water dissolve as the electrons break the rigid structure - electrolytes, something along those lines.

[katie101]

Hi Guys

I was just wondering what your thoughts were on picking up unit 2 chem without doing unit 1?

[IndefatigableLover]

Hi Guys

I was just wondering what your thoughts were on picking up unit 2 chem without doing unit 1?

Kind of depends on what your school has done on for Unit 1 of Chemistry.... for instance if you were at my school then I'd say you'd be okay because we've done all the 'non-calculation stuff' (E.g Organic Chemistry etc.) but haven't touch on the idea of moles which most schools have done (in saying that, majority of people in our cohort do know quite a bit about Chemistry so it's not really that bad).

Have a look at this and check over Unit 1 & Unit 2 and that's pretty much what you 'should' have covered or will cover in Year 11 Chemistry (what you personally learn will be dependant on your school though).