Upload
buck-cooper
View
220
Download
0
Tags:
Embed Size (px)
Citation preview
Chapter 1Matter and Measurement
Chm 108Suroviec Fall 2014
Chemistry is concerned with matter and energy and how the two interact with each other
Chemistry is a foundation for other disciplines Engineering – polymers, energy, pharmaceuticals
Health sciences Pharmacy and pharmacology Scientific writing
Chemistry
I. Atoms and Molecules3
Air is made of several components
Atoms are particles that constitute the fundamental building block of matter
Molecules are 2 or more molecules joined together
I. Atoms and Molecules4
Properties of various substances depend on the molecules and atoms that make them up
H2O vs H2O2
II. Classification of Matter
Matter has mass Not the same as weight
Matter occupies space
Phases of matter Solids
Fixed volume and shape
Liquids Fixed volume, indefinite shape
Gases Indefinite shape and volume
B. Elements/Compounds/Mixtures6
Besides classifying by state also classify by composition
Starting with all matter ask does the composition vary if you took 2 samples
Pure substance
Mixtures
Classification of Matter
III. Physical and Chemical Changes
8
We are constantly seeing changes in matter: Evaporate, rust, rotting, freezing, etc
But what happens to the molecules during these changes?
II. Physical and Chemical Changes
physical change: does not alter the composition or identity of a substance.
chemical change: alters the composition or identity of the substance(s) involved.
01_07.JPG
IV. Units of Measurements11
In 1999 the US and European scientists working together on the Mars Climate Orbiter realized after they had all ready sent the satellite off that half of the measurements were in metric and half in English. The satellite was lost.
Table 1.2 - Powers of Ten
Table 1.3 – Units and Unit Relations
IV. Units of Measurements14
A. Meter and Length B. Kilogram and Mass
IV. Units of Measurement15
C. Time and seconds D. Temperature and Kelvin
E. Volume and Density16
Volume is measurement of space and length3
Density Ratio of mass to volume
V. Reliability of Measurement17
If we were to measure water using a beaker an then again with a graduated cylinder:
Scientific measurements are reported so that every digit is certain except the last
This digit is an estimate
V. Reliability of Measurements
Significant Figures Every measurement carries uncertainty All measurements must include estimates of uncertainty with them
There is an uncertainty of at least one unit in the last digit
Significant figures are meaningful digits in measurements In 8.00 mL, there are three significant figures In 8.0 mL, there are two significant figures In 8 mL, there is one significant figure
A. Scientific Notation
The number of atoms in 12 g of carbon:
602,200,000,000,000,000,000,000
6.022 x 1023
The mass of a single carbon atom in grams:
0.0000000000000000000000199
1.99 x 10-23
N x 10nN is a number between 1 and 10
n is a positive or negative integer
A. Scientific Notation
Convert the following to scientific notation:
0.000 000 000 372 m (diameter of Na atom)
150,000,000m (distance from Earth to moon)
Accuracy – how close a measurement is to the true value
Precision – how close a set of measurements are to each other
accurate&
precise
precisebut
not accurate
not accurate&
not precise
B. Precision and Accuracy
VI. Unit Conversion
In many cases throughout your study of chemistry, the units (dimensions) will guide you to the solution of a problem
Always be sure your answer is reported with both a number and a set of units!
VI. Unit Conversions
Conversion factors are used to convert one set of units to another Only the units change Conversion factors are numerically equal to 1 1L = 1000 cm3
1cm1000
cm1000
cm1000
L13
3
3
VI. Unit Conversion
Conversion Unit 1 x 1012pg = 1 g
Convert 1.00 mg into picograms
How large is Australia in sq meters if 1 mile = 1609.34 metersand the land mass = 2,941,526 sq. miles?
How much does a person weigh in pounds if they weigh 11.29stone, given that 1 stone = 14 pounds. Use significant figures.
A. Problems with Equations25
With these problems you are going to find one of the variables given the rest.
Find the radius in cm of a water droplet with a volume of 0.06cm2 using V = (4/3)r2