ACT NO. 6: Assay of Acetic Acid in Vinegar

Question 1

A process in which acid reacts with base to produce water and salt.

Answer 1

Acid-base Neutralization

Question 2

Chemical Formula of Acid-base Neutralization

Answer 2

HCl (aq) + NaOH (aq) = NaCl (aq) + H2O (I)

Question 3

An acidic or basic titrant reacts with an analyte that is a base or an acid.

Answer 3

True

Question 4

A substance that produces protons (H+ ions) when dissolved in water.

Answer 4

Acid

Question 5

A substance that produces hydroxide ions (OH-) ions when dissolved in water.

Answer 5

Base

Question 6

A figure expressing the acidity and alkalinity of a solution on a logarithmic scale. 7 neutral, lower values are more acid, higher values more alkaline.

Answer 6

pH

Question 7

These are highly colored organic dyes that have the capability to change color in a specific pH range in a neutralization reaction.

Answer 7

Indicators

Question 8

Burette for Base

Answer 8

Mohr’s Burette (RUBBER tubing pinchcock)

Question 9

Burette for Acids

Answer 9

Geissler’s Burette (Glass stopper)

Question 10

➤C2H4O2 Or CH3COOH
➤ Organic carboxylic acid.
➤ It is a pungent smelling hygroscopic liquid.
➤Has a characteristic sour taste
➤It is the major constituent of vinegar, it finds use in the pickling of many vegetables.

Answer 10

Acetic acid

Question 11

Purity of Acetic Acid

Answer 11

NLT 36% and NMT 37% by weight of CH3COOH / C2H4O2

Question 12

How is Acetic Acid formed in a vinegar?

Answer 12

1. Fermentation processes
2. Utilizing yeast to produce alcohol from sugar
3. Utilizing bacteria to oxidize ethyl alcohol to form acetic acid.

Question 13

Gluconobacter oxidizes _______ to ____________ ?

Answer 13

ethanol to acetic acid

Question 14

Acetobacter oxidizes ?

Answer 14

ethanol first to acetic acid and then to CO2 and H2O

Question 15

Acetic acid bacteria for the commercial production of vinegar:

Answer 15

Acetobacter aceti and A. pasteurianum

Gluconobacter oxydans and its subspecies

Question 16

➤Technically vinegar is fermented food product consisting of about _____ of acetic acid per ______.

Answer 16

4g per 100 ml

Question 17

% for table vinegars

Answer 17

5-8%

Question 18

% for Pickling Vinegars

Answer 18

18%

Question 19

A 99.5-100% concentration of acetic acid. The term “glacial” refers to its property of forming crystals at 17 degrees Celsius (62.6 degrees Fahrenheit)-giving it the appearance of being frozen, like a glacier.

Answer 19

Glacial acetic acid

Question 20

Strong acid-strong base

Answer 20

HCl and NaOH

Question 21

Weak acid-strong base

Answer 21

CH3COOH and NaOH

Question 22

Strong acid-weak base

Answer 22

HCl and NH4

Question 23

Weak acid-weak base

Answer 23

CH3COOH and NH4

Question 24

• Organic in nature.
• These are substances which change color or develop turbidity at a certain pH.
• They locate equivalence point and also measure pH.
• They are acids or bases which are soluble, stable and show strong color changes.

Answer 24

Acid-base indicators