1. Introduction: Matter and Measurement
Chapter 1
Introduction: Matter and Measurement

2. Classification of Matter Matter is anything occupying space and having mass
Matter exists in 3 physical states (or phases)
1. Solid – rigid with fixed volume and shape
2. Liquid – definite volume with shape of the container
3. Gas – no fixed volume or shape, highly compressible
Mixture have variable composition
(maintain individual properties)
Homogeneous mixture – visibly indistinguishable
Heterogeneous mixture – visibly distinguishable
Solution is a homogeneous mixture

3. Physical properties include color, odor, density, melting point, boiling point, and hardness. Mixture can be separated into pure substances by physical properties: distillation, filtration, chromatography, or a magnet Pure substance, element or compound require chemical processes to break down. Intensive properties depend on the chemical, not the amount of chemical. Extensive properties depend on the amount of chemical, the mass or volume.

4. Physical change: A change in physical appearance but NOT composition.
Chemical change: The atoms are transformed into a chemically different substance.
Color change
2. Temperature change
3. Formation of a gas
4. Formation of a precipitate

5. Elements in the Earth System (% mass in Crust, Ocean, & Atmosphere)
Oxygen 49.5 %
Silicon 25.7 %
Aluminum %
Iron %
Calcium %
Sodium %
Potassium %
Magnesium %
Hydrogen %

6. Elements in the Human Body
Your body is worth less than $1.00
Oxygen 65.0 %
Carbon 18.0 %
Hydrogen 10.0 %
Nitrogen 3.0 %
Calcium 1.4 %
Phosphorus 1.9 %
Magnesium %
Potassium %
Sulfur 0.26 %
Sodium 0.14%

7. Formulate a hypothesis – possible explanation
Scientific Method
Make an observation
Qualitative – observation using descriptive words
Quantitative – observation using numbers and units
Formulate a hypothesis – possible explanation
Perform an experiment to test the hypothesis and gather data
Analyze the data
Formulate a conclusion based on data
Scientific Theory – A model or set of tested hypothesis that gives an overall explanation of some natural phenomenon, an interpretation.
Scientific Law – Summarizes what is happening.

8. Metric System (System International SI) Mass – kilogram (Kg) gram = mass of 1 mL of 4 oC Length – meter (m) length that light travels in a vacuum in 1/299,792,458 sec Time – second (s) Temperature – Kelvin or Celsius Electric current – ampere (A) Amount of substance – mole (mol) Volume – liter (L) liter = a cube 10 cm / side volume of 1 cm3 = 1 mL * 1 g H2O = 1 cm3 = 1 mL Density = mass/volume (g/mL or g/cm3)

9. Prefixes used with the metric system
page 16 your text

10. Temperature conversions K = oC + 273 ( oF – 32 ) 5/9 = oC
Heat always flows from the higher to the lower temperature substance

11. Uncertainty in Measurement: A measurement can be expressed with all certain digits plus one more uncertain.
Measurements always have some uncertainty. The degree depends on the precision of the measuring device. 50 mL beaker (markings every 10 mL) 10 certain 100 mL graduated cylinder (markings every 1 mL) 10.0 certain volumetric pipet (at ring on neck) certain

12. Which of the above targets are accurate and/or precise?
Accuracy is the “closeness” of a measured value to the true or accepted value.
Precision is the degree of reproducibility of a measured quantity. How closely individual measurements agree with one another.
Which of the above targets are accurate and/or precise?

13. Significant figures means all certain numbers plus one uncertain
Significant figures means all certain numbers plus one uncertain. Page
Nonzero integers count
Zero
leading zero don’t count
captive zero count
tailing zero count only if number contains a decimal point
360, ,400.0
Exact numbers count (example 3 apples count)
Multiple or division: answer has same number of significant figures as least precise measurement used in calculation
Addition or subtraction: answer has same number of decimal places as least precise measurement used in calculation
In a series of calculation, carry the extra digits through to the final result, then round!

14. Dimensional analysis is a method of multiplying by a factor equivalent to 1, to change the units.
Convert 15 Km/L to mi/gal

15. Density = mass/volume (units of g/mL or g/cm3)
A block of wood has a mass of 2.52 Kg. What is the density of the wood?
51 mm
1.08 m
6.2 cm

16. A chemist, trying to identify the main component of a compact disc cleaning fluid, finds that cm3 of the substance has a mass of g at 20 oC. What is the main component?
Compound 20oC Chloroform g/cm3 Diethyl ether Ethanol Isopropyl alcohol Toluene 0.867

17. Seawater has a density of 1. 03 g/mL. 3
Seawater has a density of 1.03 g/mL % of seawater by mass is salt. How many liters of seawater must be evaporated to give 75.0 g salt?
Start with known!

18. Precision can be determined by Relative Average Deviation (RAD)
RAD% = ( average deviation ) 100
Measures random error
A small RAD means that you precision is high!
Accuracy % = ( ltrue value – average measured value l )
average value
(100)
true value

19. In a titration, a student measures the concentration of an acid four times. What is the RAD?
Results deviation
M = = = =
What is the accuracy % is the true value is M?