(when assigned)
Your discussion should be well thought out paragraphs that show a consideration for how your data supports your conclusion and makes connections to the relevant theory/concepts of chemistry. You should also give a consideration of all sources of error as they relate to how you could improve the procedure and/or further investigate the problem.
You may find it helpful to refer to your text book, the internet or other source. Make sure you properly cite any sources! If you are not sure how to cite online resources, try using of Noodle Tools. Here is a great tutorial made by Dr. Cicchetti.
Also, remember that while you may discuss the ideas with other students, make sure you write independently of each other. Plagiarism is serious. It is your job to make sure that your work is your own.