mole help for yr 11?

[Kaille]

Hi guys

i've been stuck on this one question for ages!!! it'll probably pretty simple for you guys

Q. a sample of ethane, C₂H₆, contains 1.2 x 10²³atoms of carbon.

How many molecules of ethane are present?

[luken93]

Ok, so as you can see Ethane has 2 carbons present in the molecule

Therefore, for every Ethane Atom there are two carbon atoms

Therefore, for every 1.2 x 10^23 of Carbon atoms, there are 0.6 x 10^23 Ethane Molecules (6.0 x 10^22)

[HERculina]

well 1 mole = 6.02 x 10^25 'particles'

so i think the equation would be:
1.2 x 10^23 atoms of carbon = 2(x moles of ethane molecules times 6.02 x 10^25)

but imma not too sure o.o

EDIT: wait i dot get it too ... D:

[Kaille]

Thanks for the help guys!!

[Water]

well 1 mole = 6.02 x 10^25 'particles'


Correction:


6.02 x 10^23 particles = avogrados number = 1 mole xD


To Find the mole . you have atoms of  (Sample) / nA     = mol

[Hutchoo]

I wish I was doing this type of chemistry at the moment.
Unit 1 sucks. If I get questioned on "WHO wuz da main perzon dat ENV3NteD dah P3rioDIk tabl3??" I might slap someone.

[dooodyo]

nah Luken93 is correct 

[HERculina]

I wish I was doing this type of chemistry at the moment.
Unit 1 sucks. If I get questioned on "WHO wuz da main perzon dat ENV3NteD dah P3rioDIk tabl3??" I might slap someone.

isnt the mole in unit 1 chem? xD

[Hutchoo]

Yeah.. but we haven't done focused on any fun chemistry..
5 weeks of pain and boringness. D:

[Water]

I wish I was doing this type of chemistry at the moment.
Unit 1 sucks. If I get questioned on "WHO wuz da main perzon dat ENV3NteD dah P3rioDIk tabl3??" I might slap someone.

isnt the mole in unit 1 chem? xD

Just some history for you guys, might be inaccurate cause i watched it on a documentry, Lavoiser was a tax collector, and a chemist,  causing the downfall of the Monarchy and uprising of the French Revolution through excessive taxing.

Yes, you heard me, The Father of Chemistry was a Tax Collector.

[HERculina]

Yeah.. but we haven't done focused on any fun chemistry..
5 weeks of pain and boringness. D:

D: i feel for you.
 my chem teacher didnt like the history part anyway, so she tried to rush it

[Kaille]

sorry, i've got another question.

What is the total mass of ethane?

[luken93]

sorry, i've got another question.

What is the total mass of ethane?

Is this the same question or do you mean Molar Mass (You probs don't know what this is yet...)

[luken93]

Just remember all you year 11's, if you feel like you don't understand the mole ITS COMPLETELY NORMAL!!!

[nacho]

All i'll say is,
when a question asks for amount of something, your answer will be in mol
What is a mol?  A mol is the number of atoms contained 12.0 grams of Carbon-12. This number is 6.02 x 10^23 - a very large number.
The molar mass of something, for example, hydrogen is the mass of 1 mol of that substance. I.e, 6.02 x 10^23 (or 1 mole) of hydrogen atoms will weight approximately 1 gram (as given in your periodic table.)

With this knowledge, you can work out the mass, or amount in mol of anything, given you have at least 1 or the other. If you can make a logical link between the formulas and how they work, you are well on your way to acing stoich.

For example, the formula for working out mols is:

Why?
See how it works:
1 mol of hydrogen weighs 1 gram,
according to the periodic table the molar mass of hydrogen is 1 gram per mol, that is, if we have 1 mol of hydrogen atoms and weigh it, it will = roughly a gram.


So, if we have 2 grams of hydrogen, how many mol of hydrogen will we have? using , where m= 2 and = 1, we will have 2/1 = 2 mols of hydrogen.