Experiment # 6:

Preparation of Oxalic

acid

Date: December 07, 2010

Muhammad Usman

(2008-chem-02-B)

1. Cane-Sugar:

Properties of Ethanol:

IUPAC Name Sucrose

Other names Table sugar Saccharose

Appearance White crystalline carbohydrates

Structure

Molecular formula C12H22O11

Molar mass 342.07 g mol-1

Solubility in water Soluble

2. Nitric acid:

Toxic:

Fumes from concentrated nitric acid are very damaging if inhaled

Corrosive:

Concentrated and moderately concentrated solutions are very corrosive

and can cause serious skin damage

Oxidant:

Contact with the eyes can cause serious long-term damage.

Properties of Nitric acid:

IUPAC Name Nitric acid

Other names

Oxoazinic acid

Aqua fortis

Salpetre acid

Spirit of nitre

Appearance Colorless liquid

Structure

Molecular formula HNO3

Molar mass 63.012 g mol-1

Density 1.5129 g cm-3

Melting point -42 oC

Boiling point 83 oC

Solubility in water Miscible

Acidity (Pka) -1.4

Flash point Non-flammable

Preparation of oxalic acid

Chemicals Required:

1. Cane Sugar (10 g) 2. HNO3 (50 mL.)

3. H2O

Apparatus:

1. Flat Bottom Flask 2. Water bath

3. Wooden block 4. Evaporating basin

5. Filter paper 6. Beaker

Chemical Reaction:

Procedure:

1. Place 10 g of cane sugar in a 750 mL. Flat bottom flask. Then add 50 mL. Of concentrated

nitric acid and heat the flask on a boiling water bath.

2. As the mixture becomes warm a vigorous reaction accompanied by a tremendous evolution of

nitrous fumes. After that remove the flask from water bath and place it on a wooden block.

When the reaction subsides, add the hot solution into evaporating basin. Wash out the flask

with about 10 mL. Of Concentrated Nitric acid. Then evaporate the acid solution on the water

bath until it has a volume of about 10 mL.

3. Now add about 20 mL. Of water to the solution & again evaporate to about 10 mL. Cool the

solution thoroughly in ice water, oxalic acid readily crystallizes.

4. When crystallization is complete dry it by pressing between pads of drying paper.

Applications of oxalic acid:

Oxalic acid's main applications include cleaning or bleaching, especially for the removal

of rust.

About 25% of produced oxalic acid is used in dyeing processes.

It is used in Bleaches, especially for pulpwood.

Extractive metallurgy:

Lanthanide oxalates figure importantly in commercial processing of lanthanides, and are used to

recover lanthanides from solution after separation.

Miscellaneous uses:

Oxalic acid is used in the restoration of old wood.

Its reducing properties are used in the early photographic platinum/palladium printing

process.

Oxalic acid is also used for cleaning 'grubbiness' from dirty leather to get back to the

flesh of the leather, before reintroducing preservatives.

Vaporized oxalic acid, or a 3.2% solution of oxalic acid in sugar syrup, is used by some

beekeepers as a miticide against the parasitic varroa mite