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sami0201 said:



Yeah ok so that's the molar mass of it....so now how do I convert that to moles? :banghead: To go from mass to moles we do 1mol/249.682? That doesn't feel right.....I might just be going nuts though :lol:
The question is calculate the moles of anhydrous salt

I feel like I'm going in circles but I'm confusing myself...

See I'm confused because the mass of the anhydrous salt like if you put it on a scale is 1.3g (when you do crucible&salt - crucible alone) But I guess I don't need to use that number? :confused:

None of my friends can help me :scream: (talking about friends at school, not you :love: :wink: )


Deep breaths my dear. Clear thine mind.

I may have only contributed to your confusion. :reject:


Anyway, one, see that site I posted above. It's got sample calclations. ;)


Ok, you want the number of moles of the anhydrous salt (aka WITHOUT water)
So you get your mass of the salt after it's been heated.
(final mass minus mass of crucible)

You calculate the molar mass of unhydradted copper sulfate (aka the MMof CuSO4) which is 159.608 g/mol

Now, to find the moles of the unhydrated salt simply use the good old
n = m/MM

Aka
The number of moles = (dry mass) / 159.608


make sense?
 
Sad_Girl said:
Chemistry :crack:
4.gif



My feelings so perfectly captured in smiley form! :happy:

Bri :lol: Believe it or not, I could read your writing. (although, there's always typing ... ) :p

Really?! :ohmy:


You're one of the select few. :love:




I'm spamming the thread!!! :help:
 
Ok so my mass of the salt is 1.3 so I divide that by 159.608.....

approx. .0081


So the smallest whole number ratio of moles of water to moles of anhydrous salt would be...
 
~BrightestStar~ said:


Ok! :hyper:

Mine's got to do with ph, weak acids and buffers!
Have fun! :happy:

We have barely done anything with ph :sad:


How about I send you some U2 stuff instead :flirt: :wink:

OMG I have to find the empirical formula of the hydrate :crack: I know how, don't worry :wink:
This will take a year :lol:



we need a new thread!
 
sami0201 said:
Ok so my mass of the salt is 1.3 so I divide that by 159.608.....

approx. .0081


So the smallest whole number ratio of moles of water to moles of anhydrous salt would be...


PSsssst!!
The site actually does it all for you ;)


But anyhoo....
Ok, now you need to calculate the number of moles of water.


And according to the site :love:
You just divide the
moles of water by moles of salt.



And I'm taking a wild guess that the answer should be 5 :uhoh: Since you were using pentahydrate....
 
Ok nevermind :huh:

:lmao: :reject:




I should be getting some dvd's soon but you can't get mail can you? :( I'd seriously send you as a thank you :love: I don't think you know how much you've helped me in chem or math :lmao: :hug:
 
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