Hydrochloric acid (HCl) purity and concentration can be determined using titration methods.
>DETERMINATION OF ASSAY OF CAUSTIC SODA (NaOH)
APPARATUS
a). 5 ml stoppered
weighing bottle.
b). 100 ml conical
flask.
c). 10 ml pipette.
d). Burette.
e).
Nessler measuring cylinder
REAGENTS
a). Standard 1 (N)
NaOH solution.
b). Methyl Red
indicator.
ASSAY PROCEDURE OF HCL
Take a hydrochloric acid sample in a 5 ml weighing bottle.
Carefully transfer about 1 gm (weighing accurately) into a 100 ml conical flask containing 10 ml distilled water.
Titrate with 1(N) sodium hydroxide solution taken in burette using methyl red
as an indicator. 1 ml of 1(N) sodium hydroxide = 0.03646 gm. HCl.
Assay of HCL (%) = Titre value (ml) x normality
NaOH x 3.646/Weight of HCl sample taken (gm).
Molar Mass of Hydrochloric Acid
The molar mass of hydrochloric acid (HCl) is 36.46 g/mol.
It is calculated by adding the atomic masses of hydrogen (1.008 g/mol) and chlorine (35.45 g/mol).
1.008 g/mol + 35.45 g/mol = 36.46 g/mol.
>DETERMINATION OF THE STRENGTH OF
FORMALDEHYDE (FORMALIN)
How can the analysis of iron percentage in HCL solution be?
Determination of Iron In HCL: Take the Sample in a Conical Flask. Add a pinch
of APS (Ammonium persulphate) and boil well and cool. then add 10.0ML of 10%
KCNS
( Potassium thiocyanate) Solution.
Developers the red color due to the formation of ferric thiocyanate.
Transfer the solution into a 100 ML Nessler measuring cylinder and makeup.
This Red color is comparable with the red color produced by the known
volume of STD iron solution.
Percentage of
Iron (%) =(V1x0.1x100)/(VxSp.Gv.x1000)
iron conc. (as Fe)
Where
1.0 ml Std. iron solution = 0.1 mg of iron
V1= Volume of standard iron solution used
V= Volume taken from HCL sample
Analysis of Free Chlorine Percentage in HCL?
Determination
of free chlorine in HCL: Take 24.0 ml of HCL sample into a conical
flask and add 50.0 ml of chlorine-free distilled water. And titrate with
0.1 % methyl orange indicator till permanent red color.
% by mass of free chlorine = (Vx18)/Sp.Gv. *10000
V= Volume of methyl orange used for 24.0 ml of HCL sample.