Organic Chemistry experiment, preparation of oxalic acid from sucrose

I m a student of organic chemistry and today we performed an experiment about the preparation of oxalic acid, I can see all the chemicals are in chemistry have a practical use in pharmaceutical, cosmetics and industrial purpose for the production of product which are useful for human being. Same way oxalic acid is a bleaching agent, used to remove rust and stains of ink.

Apparatus:

Conical flask, beaker, funnel, filter paper, weight balance, hot plate, measuring cylinder.

Chemicals used:

Concentrated nitric acid, sucrose, ice chilled water.

Procedure:

First of all we took 2.5 grams of sucrose using spatula and measuring apparatus. Put it in Conical flask, took 10 ml of conc. Nitric acid and put it in the same flask. Place it on the hot plate , allowed it to heat at 50-60° temperature , thermometer is placed in the Conical flask to note the rise in temperature, observed Brownish fumes of nitrogen oxide gas has evolved from the flask.

Fumes of nitrogen dioxide gas was suffocating and we face problem in breathing during the Lab experiment, instructor guide us to remove conical flask from the hot plate and allow it to cool until all the fumes of nitrogen dioxide gas has been removed and colourless sample mixture will obtain.

Again we placed conical flask on the hot plate and heat Continuously between 50-60° temperature , fumes of gas still evolving but not more than in the Start of experiment. And at the end all gas evolved and a colourless solution obtained in the Conical flat. Allowed the sample mixture to cool and become normal to the room temperature. Than we added 10 ml of ice chilled water in it. Premature crystals of oxalic acid are formed. Don't shake because crystal can break.

Filtered the solution using filter paper. Oxalic acid is obtained as crystal on the surface of filter paper. Dried it weighed the filter paper plus crystals. Minus the filter paper weight and the weight of oxalic acid produced is obtained.

Which is our actual yield. Theoretical yield is obtained from the balance chemical equations. From this we found out the percentage yield of oxalic acid obtained. Which was 62 %.