Math and Measurement Unit 2

9/19/20152 Math and Measurement Use a lot of math in chemistry Learn about the mathematics of science Metrics, measurement, manipulating numbers Sometimes different than in math class

9/19/20153 Qualitative vs. Quantitative Qualitative –Descriptive measurement –Non-numeric –Examples: Color Precipitate Cold/hot

9/19/20154 Qualitative vs. Quantitative Quantitative –Quantity –Numeric –Units…. –NUMBERS ARE MEANINGLESS WITHOUT UNITS!

9/19/20155 SI Units – System International Modified metric used because… –C–Calculations and measurements are easier –D–Decimals instead of fractions –C–Changing units are easier (move the decimal) –O–Only Burma, Liberia, and the US don’t use the metric system primarily –T–There are 4 SI Units…

9/19/20156 SI Units 1. Length – meter (m) –1/10,000,000 distance from equator to North Pole –Distance light travels in 1/299,792,458 seconds

9/19/20157 SI Units 2. Mass – kilogram (kg) –1 liter of water at 4 o C –1000 grams (grams are the base unit)

9/19/20158 SI Units 3. Time – seconds (s) –1/86400 of the mean solar day

9/19/20159 SI Units 4. Volume – liters (L) –Also expressed as cubic units of length –1L = 1000 cm 3 –1 mL = 1 cm 3