In June 2014, Dr Sam Szeto joined International Scholars Tuition as a Chemistry tutor. He earned both his Bachelor of Science Honours (with First Class standing) and Doctorate of Philosophy degrees in Biochemistry from the University of Alberta (CAN). During his graduate training and academic career, Dr Szeto has been the recipient of awards for scholastic and research excellence at both the provincial and national level. These include a Natural Sciences and Engineering Research Council Postgraduate Scholarship and an Alberta Heritage Foundation for Medical Research Studentship.
When measuring the rate of a reaction, what you can't do is just measure a factor at the start or at the end. This does not work, you need to measure something continuously during the reaction, in other words, your measurements must include time . It is best to start timing at the moment that the reactants are mixed and to continue measuring for as much of the reaction as possible. You will then be able to collect sufficient data for it to be both reliable and valid, from which you can plot one or more graphs to help you to draw your conclusions.