Essential Math of Chemistry

1. Essential Math of Chemistry “No human endeavor can be called science if it can not be demonstrated mathematically.” Leonardo da Vinci (1452-1519)

2. 5.2 kg (2.9 m) 4.8 kg (23 s) kg-m = = (18 s)(1.3 s) (5.2 s)(37 s) s2 kg s The Importance of Units Units must be carried into the answer, unless they cancel. 0.64 0.57

3. Basic Algebra x + y = z Solve the following for x. x and y are connected by addition. Separate them using subtraction. In general, use opposing functions to separate things. x + y = z – y – y The +y and –y cancel on the left, x = z – y leaving us with…

4. BasicAlgebra x – 24 = 13 Solve for x. x and 24 are connected by subtraction. Separate them using the opposite function: addition. x – 24 = 13 +24 +24 The –24 and +24 cancel on the left, x = 37 leaving us with…

5. F = k x __ F x = k k k (or) F = k x ( ( ) ) __ __ 1 1 k k Basic Algebra F = k x Solve for x. x and k are connected by multiplication. Separate them using the opposite function: division. The two k’s cancel on the left, leaving us with…

6. 8 = 7 x 7 7 (or) 8 = 7 x __ 8 ( ( ) ) __ __ 1 1 x = 7 7 7 Basic Algebra 8 = 7 x Solve for x. x and 7 are connected by multiplication. Separate them using the opposite function: division. The two 7’s cancel on the right, leaving us with…

7. ( ( ) ) BAH ___ ___ BA ___ ___ 1 1 ___ TR x = = x TR TR TR H Basic Algebra Solve for x. One way to solve this is to cross-multiply. BAH = xTR Then, divide both sides by TR. BAH = xTR The answer is…

8. P1V1 P2V2 ____ = ____ T1 T2 P2V2T1 ______ T2 = P1V1 ( ( ) ) ____ ____ 1 1 (0.85 atm)(1.43 L)(373 K) _____________________ T2 = P1V1 P1V1 = (1.08 atm)(3.22 L) Solve for T2, where… P1 = 1.08 atm P2 = 0.86 atm V1 = 3.22 L V2 = 1.43 L T1 = 373 K P1V1T2 = P2V2T1 130 K

9. A General Procedure for Solving Problems • Read the problem carefully and make a list of the “knowns” and the ‘unknowns” • Look up all needed information • Your lecture notes will have much, if not all, of the needed information • Work out a plan and, following your plan, obtain an answer by carrying out the required math. • Check over your work • This is best done by estimating your answer • Ask yourself: “Does the answer seem reasonable?”

10. How to Succeed in Chemistry • Learn the language • Use the illustrations • Review your notes frequently • Work as many problems as possible • Do NOT cram for exams.

11. Hollow Penny Data Table Score side of penny in 3 locations Place penny in HCl acid overnight IN GOD WE TRUST Percent Composition LIBERTY 1982 What metal disappeared from the penny...copper or zinc? www.usmint.gov

13. THE END This PowerPoint has been made possible through LOTS of my free time!

14. Resources - Intro. to Chemistry Worksheet - vocabulary Worksheet - material safety data sheet (acetone) Activity - checkbook activity Worksheet - graphing General Chemistry PP Worksheet - real life chemistry Worksheet - conversion factors Worksheet - scientific notation Worksheet - metric article (questions) Episode 1 - The World of Chemistry Worksheet - significant digits Episode 3 – Measurement: The Foundation of Chemistry Worksheet - math review Episode 4- Modeling The Unseen Worksheet - math of chemistry Worksheet - article on the metric system Textbook - questions Lab – introduction to qualitative analysis Outline(general)