moles???????? (1 Viewer)

[samuelblayden]

I've got two thread one here and th other in chemistry HSC i need help can someone describe what are moles please

 

[Cab31]

I've got two thread one here and th other in chemistry HSC i need help can someone describe what are moles please

Moles are just ways of counting things (like for example a dozen). Where a dozen means 12, a mole is 6.022x10 to the power of 23.

Its just to simplify things. Atoms are so small that by refering to 6.022 x 10 to the power of 23 atoms as one mole, makes it easier to count things. Its easier to count 10 dozen eggs than it is to count 120 eggs - but they are the same thing. Do you get wat i mean?

 

[samuelblayden]

yea sort of but a lot more better than my teacher

 

[Cab31]

Dont worry. You'll get used to it. I was like "what the...' when i learnt it a few weeks ago at uni...but it all makes sense now

 

[samuelblayden]

yea I know but so muc was thrown at us because it is a biggish topic that my head was swimming

 

[HBK_9]

hey when is newcastle going to win a game??????

i reckon now with fat ass johns gone 4 a while, newcastle will go through the season without a win

ahahahahahahahah shit cunts

 

[samuelblayden]

HBK mate heros do lose but they come back. plus I don't care about johns now he keeps getting injured go budrus

 

[HBK_9]

ye tru buderus is better than fat ass johns

but the comeback when will that happen?

next year?

ahahahahahahah

 

[samuelblayden]

we may come back next year but we will be let me repeat that we will be the raining premiers

 

[Emma-Jayde]

Reigning premiers? Newcastle? Bah hahahahaha. Can't see that happening any time soon!!
You don't really need to know much from the moles topic for the HSC, only the formulas

 

[kazan]

how long have you been doin moles for? we start them on monday, newcastle win?

i havent heard a joke that good since 1999

 

[Guernica]

A mole is an element's atomic weight expressed in grams..i.e. a mole of oxygen is 16g..

That whole 6.022x10^23 is Avogadro's number and shows how many particles per mole... right? Or have I learnt wrong...?

 

[Emma-Jayde]

A mole is an element's atomic weight expressed in grams..i.e. a mole of oxygen is 16g..

But Oxygen is a diatomic element. If you're using Oxygen gas you need to use O₂ not O, so the Molar Mass is 32 not 16. You have to be careful with diatomic elements, such as O₂, I₂, etc

That whole 6.022x10^23 is Avogadro's number and shows how many particles per mole... right? Or have I learnt wrong...?

Yes that's right. The formula is
n = m/M
therefore
m=nM
m=1 x 16
m=16g

 

[Guernica]

But Oxygen is a diatomic element. If you're using Oxygen gas you need to use O₂ not O, so the Molar Mass is 32 not 16. You have to be careful with diatomic elements, such as O₂, I₂, etc

Mmm, yeah. I knew that. I was just using it as an example... not a very good one, I guess

Thanks

 

[Emma-Jayde]

Doesn't hurt to make sure! Some people in my year missed the bit about diatomic substances, so they had absolutely no idea that they work differently!
Good that you know it though!

 

[Fruitcake05]

How do you get the molar mass of elements with multiple valencies? (ie iron, copper)

 

[NightShadow]

the molar masses...are hwatever is on the periodic table...the electrons valances are negelible ...btw..with electron weights...aren't they taken as neglible as they dont weigh very much...thus tahts why it doesn't matter..the weights of electrons are off by two powers of magnitude compared to neurtron and proton aren't they..so it KINDA makes sense..eg...Fe = 55 point something something from memory

 

[Emma-Jayde]

The molar mass is the mass given on the periodic table. This mass is the (approximate) avg of al the common isotopes.
For example, Carbon 12 and Carbon 14 are both isotopes of carbon. The molar mass of C 12 is 12.00 and the molar mass of C 14 is 14.00, but the molar mass of C given on the periodic table is 12.01.