A Cash Still is used to determine the Volatile Acidity of wine. Our set-up comes without the chemicals, however we do supply them. Please take a look below to see what chemicals are needed.
Equipment Included:
- Boiler
- Condenser
- Heating Element
- Stand + Rod
- Drain "T"
- Band Clamp
- Band Clamp Holder
- Latex drain tube
- Latex Tubing
Chemicals Needed:
- 0.1N Sodium Hydroxide
- 25% Sulfuric Acid
- 0.02N iodine
- 1% Phenolphthalein Solution
- 1% Starch Indicator
- Antifoam
PROCEDURE
Place approximately 500mL purified water in the outer chamber of the Cash still. Start
cold water flow through the condenser. Rinse the inner chamber. Place exactly 10 mL of sample in the inner chamber. Add 2 drops of Antifoam B and rinse the funnel into the
inner chamber with a few mL of water. Place an Erlenmeyer flask under the condenser to collect the distillate.
Set the 3-way valve to vent the outer chamber and apply power to the heating element.
When steam begins to escape, close the 3-way valve. Collect 125mL of distillate.
Open the 3-way valve to vent the outer chamber and turn off the heating element power.
Refill the outer chamber with water. Open the 2-way valve to remove the contents of the inner chamber. Rinse the inner chamber twice with water before introducing additional
samples.
Add 3 drops of phenolphthalein indicator and titrate the distillate with 0.1N NaOH to a
durable pink color. Add 1mL starch indicator, 5mL sulfuric acid and titrate with 0.02N
Iodine to a faint blue color.
CALCULATIONS
Volatile acidity (gm/100mL Acetic acid) =(0.60xmL NaOH x N NaOH)–(0.60 x mL I
= 0.60x[(mL NaOH x N NaOH) - (mL I
If NaOH is 0.10N and Iodine is 0.02N = (mL NaOH x 0.06) - (mL I
2 x N I2)2 x N I2)]2 x 0.012)
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