QC Lab - Experiment 3: PREPARATION AND STANDARDIZATION OF 0.1N SULFURIC ACID SOLUTION

sulfuric acid

H2SO4

¡Colorless oily liquid

¡Soluble in water with release of heat

¡CORROSIVE to metals and tissue

¡Long term exposure to low concentration or short-term exposure to high concentrations can result to adverse health effects from inhalation

¡It is used make fertilizers, in petroleum refining, in iron and steel production

n= 2

pH 1.2

0.1 N sulfuric acid solution

inhaled

irritation of upper respiratory tract = severe lung damage

on skin

necrosis (death of body tissues)

procedure

¡Using pipette, add slowly with constant stirring, 1.6 mL of condensed Sulfuric acid to 500 mL of distilled water in a volumetric flask

standardization

1.Weigh accurately 0.15g of Anhydrous Sodium carbonate, previously heated at 270 degrees Celsius for 1 hour. Dissolve it in 15mL of distilled water.

2.Add 2 drops of Methyl Red TS and titrate with Sulfuric acid solution until the solution turns faintly red.

3.Heat the solution to boiling and continue the titration.

4.Heat again to boiling and take note if the solution transitions from red to yellow.

5. Titrate further as necessary until the red color becomes permanent.

6. Calculate the Normality of your standardized solution.

7. Label the container properly with the actual normality computed.

normality

mass of PS/molar mass of PS/ n of PS x 1000/titer

anhydrous sodium carbonate

primary standard (in erlenmeyer)

sulfuric acid ()

titrant (burette) + methyl red

methyl red

indicator

faint red

endpoint from yellow

heat

to increase rate of reaction between sulfuric and sodium because it is slow (until no longer affected by continued boiling)