Re: [Histonet] Normal solution

From:Rene J Buesa

No, you cannot. The thing is that in order to have the needed MASS from a liquid chemical you have to introduce in the calculation 2 other variables:
  1- density of the chemical (= g/mL), and
  2- concentration (% of the chemical in liquid form).
  For example: lets suppose you want to prepare a 1 Normal solution of HCl (hydrochloric acid).
  In this case: the molecular weight (MW) = 36.5
  the density = 1.19 g/mL (find that in the label) and
  purity (or concentration) = 37% (also found in the label).
  So in order to have a 1N solution of HCl you will need:
  36.5 g DIVIDED by (1.19 g/mL x 0.37) = 82.9 mL of H Cl + distilled water UP TO 1,000 mL
  Hope I have been apble to explain it!
  René J.

Dolors Fuster  wrote:
  *Hi histonetters!

I was looking in archives how to made a Normal solution and found the following explanation:* we go. a 1N solution equals 1 gram-equivalent weight of compound in a liter of water. the gram-equivalent weight 
is determined by dividing the molecular weight by the number of hydrogen ions (or -OH groups) per formula. 
so, in the case of sodium hydroxide (NaOH....a single hydroxyl group) the gram-equivalent weight is 40g 
(ok....i'm rounding a bit for simplicity). 
so a 1N solution would be 40g/L.....therefore, a 2N solution would be 80g/L and a 5N solution would be 200g/L.

carrie kyle-byrne

*It's a really good explanation for me but I still have a question. Have I to follow the same 
procedure with liquids? 
What have I to do if I need a Normal solution of hydrocloric acid, nitric acid, iso-propylic alcohol 
or any other liquid compound?
Have I to use the same amount of ml than gr used with solids applying the same formula?

Thanks in advance

Dolors Fuster 
Tècnic Especialista en Anatomia Patologica i Citologia
Facultat de Medicina
Dep. d'Anatomia i Embriologia Humana
Universitat de Barcelona*

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