Experiment #1: Precision and Accuracy
In this laboratory we applied the concepts of accuracy and precision. We used electronic balances to generate our data to prove the usefulness of our concepts.
* 1 Erlenmeyer
* 1 Graduated Cylinder of 50ml
* 1 Timer
* 1 Electronic balance
* 1.84 grams of CaCo3
* 50ml of HCl
Our group gathered the materials. First, we got the Erlenmeyer flask and added 50ml of HCl, measured with a Graduated Cylinder of 50ml. Then we added 1.84g of CaCo3, measured with the electronic balance, into the Erlenmeyer with the 50ml of HCl. Immediately, we placed the Erlenmeyer flask with the solution on top of the electronic balance to observe the changes in its mass. Our group checked the changes for 5 minutes writing down the results each 15 seconds. The weight of the Erlenmeyer flask plus the solution dropped gradually at a rate of 0.02 grams each 15 seconds, starting at 149.00 with a big drop at the first 15 seconds to 148.88g and finishing the rest of the 4 minutes 45 seconds at 148.52g.
It is not just doing an experiment without taking your time to analyze what those numbers and values are telling you, but what is important here is to be very precise with your results, and how do you do that? By taking into account the amount of significant figures you’re working with. By working with them, the less percentage of error your experiment will have.