Ethandioic acid (also known as oxalic acid) is a chemical compound with the formula H
2C
2O
4. This dicarboxylic acid is a relatively strong organic acid. This acid is widely used as an purifying agent in pharmaceutical industry.
(Source -
http://en.wikipedia.org/wiki/Ethandioic_acid)
However, ethandioic acid is very poisonous.
Oxalic acid is a strong poison. The toxic symptoms from ingestion include vomiting, diarrhea, and severe gastrointestinal disorder, renal damage, shock, convulsions, and coma. Death may result from cardiovascular collapse. Oxalic acid may be absorbed into the body through skin contact. It is corrosive to the skin and eyes, producing burns.(Source -
http://www3.fed.cuhk.edu.hk/chemistry/oxalic.html)
If the purpose of the practical work is merely to prepare a standard solution, then the use of toxic ethanedioic acid is not essential. If you really want to prepare a primary standard of an acid, potassium hydrogen phthalate (C
8H
5O
4K) is much better than ethandioic acid. It is a monoprotic acid (HOOCC
6H
4COO- K+) with low toxicity. Potassium hydrogen phthalate is a good primary standard because of the following properties:
1. High purity
2. Stable in air
3. Easily soluble in water
4. High molar mass
5. Complete and rapid acid-base reaction
I thought I would use the mole concept as an example to show her how to do it. Here's my finished work:
It's quite easy, actually. After you have finished, just go to Menu>File>Save As... and save your work as JPEG File Interchange Format and you are done! Simple?
Actually, creating graphics using the computer is quite easy, and the feeling looking at your finished work is really great. Thanks to ocarina-sensei, anyway. She's truly my good mentor.
