My practical exam's like a experiment exam, where you do the experiment and the teacher marks based on the way you do it, and you record the readings down and draw graphs. If you do the procedures incorrectly, you would be penalised, what's more if you do it in a unsafely way (spilling water, breaking stuff, and even not looking at the measuring cylindal in the wrong way) you would be penalised.
And I was so god damn nervous that I wrote my graphs axis wrongly!
Go and study now, I regretted not studying. Kakaka.