1. Matter, Energy and Measurement
Chemistry B11
Chapter 1-2
Matter, Energy and Measurement

2. Chemistry and our life

3. Chemistry & Matter Matter: has mass and takes space.
Chemistry: science that deals with matter and its changes.
Central to Science
All sciences are connected to chemistry.

4. evaporation of water, melting of a solid, sublimation
Changes
Chemical change (chemical reaction):
substance(s) are used up (disappear) → others form
burning paper or dissolving salt
Physical change: identities of the substances do not change.
(change of state)
(Gas, Liquid, Solid)
evaporation of water, melting of a solid, sublimation

5. theory: is the same as a hypothesis except that we have a stronger
Scientific method
fact: is a statement based on direct experience.
hypothesis: is statement that is proposed without actual proof.
theory: is the same as a hypothesis except that we have a stronger
belief in it because there is more evidence, some proof, supporting it.
serendipity: observation by chance (luck).

6. Rounding and Decimals Significant Figures
Round down for numbers between
0-4 and up for 5-9
Using the correct number of
Significant figures
Addition / Subtraction least number of decimals
Multiplication / Division least Sig. Figs.

7. Exponential notation based on powers of 10
10000 = 1× = 1×10-4
= 4.5×106
= 7.8×10-5
94800 = 9.48×104
= 1.21×10-2
Positive power: greater than 1
Negative power: Less than 1

8. Exponential notation
Power, Exponent
9.23 1025
Coefficient
Base

9. Exponential notation (3.62 ×106)(7.43 ×103) = 26.90 ×109 = 2.69 ×1010
4.62 ×107
= 2.00 ×102
2.31 ×105
Moving the decimal point to right
Decreasing the power one point
Moving the decimal point to left
Increasing the power one point

10. Measurements

11. All measurements are inherently Limited by the accuracy of the
Measurement consists of two parts:
Number - Unit
All measurements are inherently
Inaccurate!
Limited by the accuracy of the
Measuring device!
2 pounds
Unit
Number

12. Measurement and Units
Metric system or SI (International System of Units)
meter, liter, gram …
English system (used in the United States)
miles, gallons, pounds …
Advantages of SI: we have base unit for each kind of measurement.
Other units are related to the base unit by powers of 10.

13. Prefix (symbol)
Value
giga (G)
109
mega (M)
106
kilo (k)
103
deci (d)
10-1
centi (c)
10-2
milli (m)
10-3
micro (µ)
10-6
nano (n)
10-9
base unit of length: meter (m)
1 kilometer (km) = 1000 meter (m)
1 centimeter (cm) = 0.01 meter (m)
1 nanometer (nm) = 1×10-9 meter (m)
base unit of mass: gram (g)
1 kilogram (kg) = 1000 gram (g)
1 milligram (mg) = gram (g)
base unit of volume: liter (L)
1 milliliter (mL) = liter (L)
1000 milliliter (mL) = 1 liter (L)
1 mL = 1 cc = 1cm3 1L = 1dm3
base unit of time: second (s)
60 seconds (s) = 1 minute (min)
60 minutes (min) = 1 hour (h)

14. Tools (equipment) of measurement
Length: Meterstick or Ruler
Volume: Graduated cylinder, Pipette
Mass: Balance

15. a measure of the energy in a system
Temperature
a measure of the energy in a system
English system
Fahrenheit (°F)
metric system or SI
Celsius or centigrade (°C)
°F = 1.8 °C + 32
°C =
°F – 32
1.8
Kelvin scale or absolute scale (K)
K = °C +273
°C = K – 273

16. Temperature

17. Conversion of Units Factor-Label method 25kg = ? lb 25kg × 1 kg
78 mile = ? km
78mi ×
1 mi
1.609 km
= 130 km
45 m/h = ? in/min 45 m h ×
1 m
39.37 in
= 30. in/min
60min
1 h

18. States of Matter

19. No units (dimensionless)
Density and Specific gravity
density: mass per unit volume
d = m V
d: density (g/mL or g/L) m: mass V: volume
Specific gravity:
SG =
dsubstance
dwater
No units (dimensionless)
Relative to water
Hydrometer

20. Energy Kinetic energy (KE): energy of motion KE = ½ mV2 V: velocity
Potential energy: stored energy
Law of conservation of energy

21. Heat and Temperature units of heat: calorie (cal) or joule (J)
1 cal = J
Amount of heat = specific heat × mass × change in temperature
Amount of heat(cal) = SH × mg × (T2 – T1)
T2 = final temperature (C)
T1 = initial temperature (C)
SH = Specific heat (cal/g °C)
Water = 1