hdcwr0x2 - 25-5-2005 at 15:56
Ok, so at the hardware store here they sell ~32% HCL in gallon jugs. How would I calculate molarity from percentage? Would I find the moles of HCL in
1 liter of it, and simply multiply by the percentage over 100 and get molarity from there? I know this is a stupid question but I'm a little
confused.
Darkblade48 - 25-5-2005 at 17:49
First, you'd have to know the solution density (let's assume it's 1.19 g/mL in this example)
So with 1L of HCl, you'd have something that has a mass of 1190 g.
Of this, 31.45% is HCl, so that's 374.255 g of HCl. Divide this by the molar mass to get the number of moles --> 10.25 moles
Now, since there's only 1 L, it's 10.25 moles/litre = 10.25 M
So, the solution is about 10 M HCl
hdcwr0x2 - 25-5-2005 at 17:57
Thanks, I was thinking something like that but I wasn't sure.
Borek - 28-5-2005 at 01:58
Check my program CASC - concentration and solution calculator. Density tables are built in, so such conversion is just a matter of few clicks. Oh, and
you have to enter 32 
BromicAcid - 28-5-2005 at 07:28
Converting percent (%) solution to molarity (M)
My origional thread on the subject.
The conversion is simple, although I must confess I haven't converted between percent solution to molarity in some time, once I figured out how I
converted all of my soluitons I had (such as bleach and HCl and HBr and isopropyl alcohol) to their respective molarities and labeled them. And
Borek, I noticed that your program has a liscense that you have to buy after 30 days to continue using it, how much does that cost?
Borek - 28-5-2005 at 14:36
There are two types of license - normal (about $60) and light (about $20) - the main difference is that light version doesn't have full editable
database, but is limited to the 10 compounds present in demo version. You fill find all the information on my page - select "price" on the
left menu.
Prices in USD are only approximate, as they depends on the conversion rates between EUR and USD.