When should we use the density of water as 0.997g mL^-1, vs assuming that the density of water is just 1? For calculations involving finding Q with the specific heat capacity of water, I'm not sure as to when the given volume of water should be multiplied by 1 or by 0.997. I know in the databook it gives the density of water as 0.997g mL^-1 to be at 25 degrees C, so should I be using it in those Q calculations or not?
Hi! It is best to use the density of water as given in the data booklet, as this is what VCAA would want to see in your working out
anyone have any Ideas on nailing experimental design questions? and where to find them?
Hi! You can find some practise experimental design questions in past VCAA exams - they're usually right at the end of the exams! As for nailing them, practise is the best, as you will find that the answers to experimental design questions start becoming repetitive after a while. Do some practise ones and get your teacher to mark and give you some feedback. However, some things you should study/look over are:
- Types of errors (systematic, random etc)
- Structures of aims, conclusions and hypothesis
- Different ways of representing data
- difference between accuracy/precision
Also, be familiar with the specific errors that can occur in certain experiments. Especially for titrations and calorimetry. What could go wrong if you wash an apparatus with water? What factors impact the energy transfer in a calorimetry experiment?
Hope this helps!