Dr. Stephen Lukacs (May 2012)
The minimum necessary skills for weighing solids and liquid handling to properly make solutions and serial dilutions to create standard solutions for instrumental calibration.
(February 2013) No Measurement is Ever Exact.
Every measurement is precise, but never exact. Significant figures are the proper expression of that precision and the process of carrying through by the weakest link.
Carefully watch this PodCast because it is not just a matter of recognizing and counting the significant figures, but carrying them through addition/subtraction and multiplication/division properly. Those use two different rules, so see the differences and practice them properly, which both will be used to properly calculate the molar mass in the next PodCast.
(February 2013) Weighing the mass of reactants or products based on the molecular formula is an important first step to knowing the amount of the substance in moles.
Being in science and medicine, you should verify all things, even the molar mass if it is printed on the stock bottle from the manufacturer. So get used to calculating molar masses fast and efficiently.
Be sure the carefully watch how the significant figures are calculated, using both the multiplication/division rule and then the addition/subtraction rule.
(February 2013) Over 99% of all reactions occur in solution. Your very existence is the effect of billions of reactions happening every second in the bag of mostly water you call your body.
This PodCast also demonstrates the calculations and procedure to create a proper solution in the laboratory.
(February 2013) This PodCast demonstrates the in-lab/hands-on techniques for using the proper glassware for analytical/quantitative precision up to four significant figure.
It also shows the liquid handing techniques to do serial dilutions to four significant figures. The concept and calculations of which will be covered in more detail in the following PodCast.
Practice these techniques with water. Practice them exactly as you see them in this PodCast, with the practice will come a smoothness, and your speed will also increase. That grace is what you want in the laboratory.