More Hydrochloric acid...?

Question

Thanks to those of you who replied to my first question. As there appears to be more than one answer, I'll clarify a little. The HCl was ordered by a colleague. I wanted 0.1M bench acid for school use but he ordered a litre of 35% HCl (That's what it says on the bottle). As a biologist who's too lazy to work out the molarity based on the molecular mass of HCl, I thought I'd ask you kind people... So am I right in thinking that it's around 10-12molar? That's a lot of dilution for me to do! I thought it was strong when I opened the bottle and chlorine gas appeared!

Answer 1

Acid ordered in this fashion is considered to be 12 molar. The first usual dilution is down to 6 molar. Then, in your case, go to one molar, then to a tenth. Make one liter of it each time.

It was HCl that appeared when the bottle was cracked open, not chlorine gas.

Too lazy, hmmm. Learn the technique please!

Oh yeah, use volumetric glassware when doing the dilution. Please, if you do learn the technique, learn it correctly.

Answer 2

I wonder if you need standard diluted hydrochloric acid ? anyway i dont think so but you can titrate your diluted acid against standard base as NaOH or KOH to get the accurate Molarity of your acid. you can find your HCl bottle molarity written on the bottle or you can calculated by using the density then you can dilute to your desired concentration by using this equation
Volume 1x Molarity 1 = Volume 2 x Molarity 2

Answer 3

SAFETY NOTE: do not pipette acids, especially concentrated acids, by mouth!

How accurate do you want the 0.1M? Starting from your concentrated material, it will not be spot on, because you don't know exactly how much HCl gas escaped.

So is precise concentration is important you would need to titrate against standard alkali. You're probably better off buying standardised acid to start with. I don't know if you can get 0.1M, but you can certainly get 1.0M and then dilute by a factor of 10.