Dr. Stephen Lukacs (May 2012)
This series of PodCasts presents the most critical concepts and practices required for your mastery of introduction to, principles of, and general chemistry. It is also critical to lay this as a solid foundation for more advanced, but practical, classes like chemical instrumentation. The topics in this series of Podcasts cover scientific number and notation, significant figures, and conventional conversions, aka, dimensional analysis.
(January 2013) This lecture is about the three necessary components of a scientific number: (i) the size or magnitude of the number itself, (ii) the unit of measure to give context and meaning to that number, and (iii) the expression of proper precision through significant figures.
Remember and practice: (i) the size or magnitude of the number itself, (ii) the unit of measure to give context and meaning to that number, and (iii) the expression of proper precision through significant figures.
(January 2013) For the very BIG and the very small. Scientific notation does two things for us. It is great for expressing very big and very small numbers and it also unambiguously expresses the measurement to the proper significant figures.
Scientific notation does two things for us: (i) allows us to express very big and very small numbers in a compact form, and (ii) unambiguously communicate the proper significant figures for us.
(January 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 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.
(May 2012) AKA: Dimensional Analysis. The unit-cancellation method becomes invaluable later when we turn to chemical conversions.
The above lecture is the first part of conventional conversions, miles to kilometers, inches to meters, etc. This part covers the essential concepts and the basis of the unit-cancellation method with practical examples.
(May 2012) AKA: Dimensional Analysis. The unit-cancellation method becomes invaluable later when we turn to chemical conversions.
The above lecture is the second part of conventional conversions, miles to kilometers, inches to meters, etc. This part covers SI prefixes and the metric system along with multi-step conversion processes through practical examples.
(May 2012) AKA: Dimensional Analysis. The unit-cancellation method becomes invaluable later when we turn to chemical conversions.
The above lecture is the third part of conventional conversions, miles to kilometers, inches to meters, etc. This part covers more in depth multi-step conversion processes along with cubic volumes to regular volumes and the all important concept of density.
(August 2019) This is a summary revisited more-modern online lecture of the above three "Conversions" lectures. Please ignore any external comments or references to chapters and such throughout this lecture.
(August 2019) Temperature conversions don't use the unit-cancellation method, but actual algebra type equations. This online lecture shows you how to handle temperature conversions with a hopeful review of algebra.
(December 2014) Periodic Table, Conventional Conversions, SI Prefixes, Polyatomic Ions, Chemical Conversions, Chemical Equations, Table of Electronegativities, and the Redox Recipe.
Print it. You can use all of it everywhere and anytime.