Squall
Harmless
Posts: 37
Registered: 22-8-2007
Member Is Offline
Mood: Alive
|
|
HCl concentation
I have some Hydrochloric acid that i would like to find the molarity of. The container says that the HCl is 31.45%. I am wondering if there is a way
to convert that into moles. and does the percentage mean that there are 31.45g of HCL in every 100ml of solution.
|
|
|
chromium
Hazard to Others
Posts: 284
Registered: 27-6-2005
Member Is Offline
Mood: reactive
|
|
No. This means that 100g of solution contains 31.45g HCl. Your HCl is very near to 10 mol/l or 36.5g/100ml.
Concentrations can be easily converted to different systems if you know specific gravity of solution.
[Edited on 23-11-2007 by chromium]
When all think alike, then no one is thinking. - Walter Lippmann
|
|
|
chloric1
International Hazard
Posts: 1127
Registered: 8-10-2003
Location: GroupVII of the periodic table
Member Is Offline
Mood: Stoichiometrically Balanced
|
|
Yes chromium is spot on with this. The bottle should give you a baume measurement. Like 20 degrees baume I believe. Go to a used book store and try
to find Langes Handbook of Chemistry or CRC Handbook of chemistry and Physics, especially the older ones! They will help you with your measurement
conversions. It is always good to find the specific gravity of an aqeous solution. Everything else can be determined from this.
Fellow molecular manipulator
|
|
|
Squall
Harmless
Posts: 37
Registered: 22-8-2007
Member Is Offline
Mood: Alive
|
|
Chloric you are right the bottle does say 20 degree baume. but i have no idea what that means. And Thanks for the handbook idea.
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Squall
Chloric you are right the bottle does say 20 degree baume. but i have no idea what that means. And Thanks for the handbook idea.
|
http://antoine.frostburg.edu/chem/senese/101/measurement/faq...
some tables
http://books.google.com/books?id=gzlfdieJISMC&pg=PA76&am...
This book - old but still use and free download - has similar tables
Standard Methods of Chemical Analysis: A Manual of Analytical Methods ... By Wilfred Welday Scott
http://books.google.com/books?id=jv0uKgPUKLIC&pg=PR28&am...
or
http://www.archive.org/details/standardmethodso00scotrich
|
|
|
Squall
Harmless
Posts: 37
Registered: 22-8-2007
Member Is Offline
Mood: Alive
|
|
Thank You so much for the links.
Heres what I've come upwith.
According to the charts the specific gravity of a 20 degree baume solution is 1.6. So the solutiuon weighs 1.6g .
So next i multiply 1.6x1000 to get the amount of grams in a liter. Next i multiplied the resulting product by the percentage which is 31.45 so
1600x.3145=503
So the solution contains 503grams of HCl. next i multiply 503x31.45=16. So if i did my calculations correctly this tells me that my acid's
molarity is 16Moles.
I appreciate all of you help and would like to know if my calculations are done correctly. Thank you again
[Edited on 23-11-2007 by Squall]
|
|
|
evil_lurker
National Hazard
Posts: 767
Registered: 12-3-2005
Location: United States of Elbonia
Member Is Offline
Mood: On the wagon again.
|
|
Well, to calculate s.g. based on degrees baume, one would do the following.
145/(145-degrees baume)= s.g.
145/(145-20) =s.g of 1.16
1.16 x 1000 = 1,160g per 1000ml
1160 x .3145 = 364.82g
364.82 / 36.46 (molecular mass of HCl) = 10.00 moles per liter
This corresponds with the following chart below:
http://en.wikipedia.org/wiki/Hydrochloric_acid
Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in
beer.
|
|
|
Squall
Harmless
Posts: 37
Registered: 22-8-2007
Member Is Offline
Mood: Alive
|
|
Oh i see I made a careless mistake and wrote the specific gravity wrong 1.6 instead of 1.16. I need to watch out for stuff like that, but thank you
for pointing that out i appreciate all of your help.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
