Read "ACS Style Guide, a Manual for Authors and Editors" published by the American Chemical Society. Familiarize yourself with the ACS conventions for writing research papers. Information is generally presented under the headings of introduction, materials and methods, results, discussion and references.
Write an introduction that covers the scientific background of your topic. Give information about the gaps in this knowledge and correlate the purpose of your particular work. Include the hypothesis of your experiment. Keep the wording of the hypothesis simple, clear and specific, and state the relationship you expect between the independent and dependent variables. For example, "It was hypothesized that as the pH of the reaction mixture became more acidic, the reaction rate decreased."
Include experimental information of the materials you used and the procedure you followed in the materials and methods section of the paper. Use discretion in deciding how much detail to provide. Mention chemical grades and instrumental make and model as and when they appear in the procedure. If the procedure you used is a modification of an existing standard method, reference the publication that explains the method and explain only your modifications. Mention the controls you used and why you chose them. Make sure your information allows readers to understand your experiment and to duplicate it if desired.
Study the data you have collected. Describe the results using tables, graphs and diagrams. Provide all figures a number and a descriptive title. Ensure you label the axes of graphs with names and units of the variables. Specify units for a parameter under the respective table column. Point out trends you observed that are relevant to your hypothesis.
Draw conclusions from the data in the discussion section. State if the results support your hypothesis. Acknowledge deviations you encountered or suggestions for improvement. Relate your work to previous work in the same field and explain the implications of your results. Avoid using words such as "proved" and "disproved." Use words such as "suggested" and "supported."
Use the past tense for citing past work, describing your hypothesis and in the materials and methods section. Write the results and discussion sections of the paper in the present tense. Write in the third person, avoiding personal pronouns such as "I," "me," "we" and "our."