moley moles (1 Viewer)

[ram14]

I'm absolutely shocking with mole calculations, I have no idea whats goin on with em so i was wondering if any of you guys know where I can learn mole calculations from scratch to HSC mole calculations. Any good sites, book refrences or notes would be excellent.
Thanks.​

 

[Forbidden.]

No I thought 1 Mole was the equivalent to 1 atomic weight of a substance in grams.

 

[idling fire]

This is what I know (or think I know) about moles.

A mole is an exact number of atoms, Avagadro's number to be precise. 6.022*10^23 atoms make up one mole of an element, while 6.022*10^23 molecules make up one mole of a compound.

If you have the mass (grams) of a substance, you can determine the number of moles you have using the formula n=m/M where n=no. of moles, m=mass, M= molecular mass (in atomic mass units, i.e. off the periodic table.)

If you want exactly one mole of an element, just look at its molecular mass, and use that in grams. For example, I want 1 mole of carbon. On the periodic table it says it is 12 a.m.u. So I weigh 12 grams, and I have one mole. You can see that it works using the equation.

So then if you have a particular number of moles and want to know how many atoms, simply divide by Avagadro's number (6.022*10^23) and that's that.

The number of moles reacting in an experiment can be seen from the balanced chemical equation. eg.
2Na + Cl2 -> 2NaCl
2mol + 1mol -> 2mol

Hope that was useful...

 

[ram14]

Hye guys,
Thanks for ya help but I mean i really have no Idea about thw whole concept of it, Whats the point...I need some good explanation and a shite loada practice questions...

 

[tennille]

If you check here, there are some resources for both the preliminary and HSC courses. There are past/practise papers located here. There are also some stickied threads in this forum that provide resources. But if you have any questions yourself from school, please post them up and we can help you.