1. Chemistry: The Study of Change
Chapter 1
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2. Chemistry: A Science for the 21st Century
Health and Medicine
Sanitation systems
Surgery with anesthesia
Vaccines and antibiotics
Gene therapy
Energy and the Environment
Fossil fuels
Solar energy
Nuclear energy

3. Chemistry: A Science for the 21st Century
Materials and Technology
Polymers, ceramics, liquid crystals
Room-temperature superconductors?
Molecular computing?
Food and Agriculture
Genetically modified crops
“Natural” pesticides
Specialized fertilizers

4. The Study of Chemistry
Macroscopic
Microscopic

5. Qualitative data consists of general observations about the system
The coffee is hot
The boy is tall
Quantitative data comprises numbers obtained by various measurements of the system.
The coffee is heated to 97°C
John is 5 ft 6 in tall

6. The scientific method is a systematic approach to research
A hypothesis is a tentative explanation for a set of observations
tested modified

7. Force = mass x acceleration
A law is a concise statement of a relationship between phenomena that is always the same under the same conditions.
Force = mass x acceleration
A theory is a unifying principle that explains a body of facts and/or those laws that are based on them.
Atomic Theory

8. Problem 1.3
Classify the following statement as (a) qualitative (b) quantitative 1.The sun is approximately 93 million miles from earth. 2. Leonardo daVinci was a better painter than Michelangelo. 3.Ice is less dense than water. 4.Butter tastes better than margarine.

9. Problem 1.4 (a)
Classify the following statement as a (a) hypothesis (b) law (c) theory 1.Beethoven’s contribution to music would have been much greater if he had married. 2. An autumn leaf gravitates toward the ground because there is an attractive force between the leaf and the earth. 3. All matter is composed of very small particles called atoms

10. Chemistry is the study of matter and the changes it undergoes
Matter is anything that occupies space and has mass.
A substance is a form of matter that has a definite composition and distinct properties.
liquid nitrogen
gold ingots
silicon crystals

11. Heterogeneous mixture – composition is not uniform throughout.
A mixture is a combination of two or more substances in which the substances retain their distinct identities.
Homogenous mixture – composition of the mixture is the same throughout.
clear juice (apple, cranberry), bronze, solder
Heterogeneous mixture – composition is not uniform throughout.
cement,
iron filings in sand

12. Physical means can be used to separate a mixture into its pure components.
distillation
magnet

13. dry ice – carbon dioxide
A compound is a substance composed of atoms of two or more elements chemically united in fixed proportions.
Compounds can only be separated into their pure components (elements) by chemical means.
lithium fluoride
quartz
dry ice – carbon dioxide

14. 114 elements have been identified
An element is a substance that cannot be separated into simpler substances by chemical means.
114 elements have been identified
82 elements occur naturally on Earth
gold, aluminum, lead, oxygen, carbon, sulfur
32 elements have been created by scientists
technetium, americium, seaborgium
Element 118 discovered in 2006!

16. Classifications of Matter

17. Problem 1.16(a)
Classify the following as a(n) (a) element (c) homogeneous mixture (b) compound (d) heterogeneous mixture filtered sea water Helium gas Kosher salt (sodium chloride) A bottle of soda (capped, unshaken) A milkshake Filtered air in a bottle concrete

18. A Comparison: The Three States of Matter

19. The Three States of Matter: Effect of a Hot Poker on a Block of Ice
solid
liquid
gas

20. Types of Changes
A physical change does not alter the composition or identity of a substance.
ice melting
sugar dissolving
in water
A chemical change alters the composition or identity of the substance(s) involved.
hydrogen burns in air to form water

21. Problem 1.12(a)
Does the following describe a (a) chemical change or a (b) physical change?
The helium gas inside of a balloon tends to leak out after a few hours.
Frozen orange juice is reconstituted by adding water to it.
The growth of plants depends on the sun’s energy in a process called photosynthesis.
A spoonful of table salt dissolves in a bowl of soup.

22. Extensive and Intensive Properties
An extensive property of a material depends upon how much matter is is being considered.
mass
length
volume
An intensive property of a material does not depend upon how much matter is is being considered.
density
temperature
color

23. Interestingly, the process of measuring mass is called weighing!
Matter - anything that occupies space and has mass.
mass – measure of the quantity of matter
SI unit of mass is the kilogram (kg)
1 kg = 1000 g = 1 x 103 g
weight – force that gravity exerts on an object
W = m x a
SI unit of force is the Newton (N)
1 N = 1 kg∙m/s2
Interestingly, the process of measuring mass is called weighing!

24. A 1 kg mass weighs almost 6 times more on earth than on the moon!
Mass is constant, while weight is dependent on location
On the moon, a = 1.67 m/s2
W = m x a = 1 kg x 1.67 m/s2
1.67 Newton
On earth, a = 9.81 m/s2
W = 1 kg x 9.81 m/s2 = 9.81 kg∙m/s2
9.81 Newton
9.81 Newton/1.67 Newton = 5.87
A 1 kg mass weighs almost 6 times more on earth than on the moon!

25. International System of Units (SI)

27. Volume – SI derived unit for volume is cubic meter (m3)
1 cm3 = (1 x 10-2 m)3 = 1 x 10-6 m3
1 dm3 = (1 x 10-1 m)3 = 1 x 10-3 m3
1 L = 1000 mL = 1000 cm3 = 1 dm3
1 mL = 1 cm3

28. Density – SI derived unit for density is kg/m3
1 g/cm3 = 1 g/mL = 1000 kg/m3
density =
mass
volume
d = m V
A piece of platinum metal with a density of 21.5 g/cm3 has a volume of 4.49 cm3. What is its mass?

29. Problem 1.22
The density of ethanol, a colorless liquid that is commonly known as grain alcohol, is g/mL. Calculate the mass of 17.4 mL of the liquid.

31. A Comparison of Temperature Scales1K
K = (0C C)
1 0C
273 K = 0 0C
373 K = 100 0C
0F = x 0C F
9 0F
5 0C
32 0F = 0 0C
212 0F = 100 0C

32. Convert 327.5 0C to degrees Fahrenheit.
Convert F to degrees Celsius.
Convert 77 K, the boiling point of liquid nitrogen to degrees Celsius.

33. Problem 1.24(a)
Normally the human body can endure a temperature of 105 °F for only short periods of time without permanent damage to the brain and other vital organs. What is the temperature in °C?

34. Problem 1.24(b)
Ethylene glycol is a liquid organic compound that is used as an antifreeze in car radiators. It freezes at °C. Calculate the freezing point in °F.

35. Problem 1.24(c)
The temperature of the surface of the sun is about 6300 °C. What is this temperature is °F?

36. Problem 1.24(d)
The ignition temperature of paper is 451 °F. What is the temperature in K?

37. 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:
1.99 x 10-23
N x 10n
N is a number
between 1 and 10
n is a positive or
negative integer

38. Scientific Notation Addition or Subtraction 568.762 0.00000772
move decimal left
move decimal right
n > 0
n < 0
= x 102
= 7.72 x 10-6
Addition or Subtraction
Write each quantity with the same exponent n
Combine N1 and N2
The exponent, n, remains the same
4.31 x x 103 =
4.31 x x 104 =
4.70 x 104

39. Scientific Notation Multiplication Division
(4.0 x 10-5) x (7.0 x 103) =
(4.0 x 7.0) x (10-5+3) =
28 x 10-2 =
2.8 x 10-1
Multiply N1 and N2
Add exponents n1 and n2
Division
8.5 x 104 ÷ (5.0 x 109)=
(8.5 ÷ 5.0) x =
1.7 x 10-5
Divide N1 and N2
Subtract exponents n1 and n2

40. Significant Figures Any digit that is not zero is significant
1.234 kg significant figures
Zeros between nonzero digits are significant
606 m significant figures
Zeros to the left of the first nonzero digit are not significant
0.08 L significant figure
If a number is greater than 1, then all zeros to the right of the decimal point are significant
2.0 mg significant figures
If a number is less than 1, then only the zeros that are at the end and in the middle of the number are significant
g 3 significant figures

41. How many significant figures are in each of the following measurements?
24 mL
3001 g m3
6.4 x 104 molecules
560 kg

42. Problem 1.34
How many significant figures are in each of the following measurements?
0.006 L dm
60.5 mg
605.5 cm2
960 x 10-3 g
6 kg
60 m

43. Significant Figures Addition or Subtraction
The answer cannot have more digits to the right of the decimal
point than any of the original numbers.
89.332
1.1 +
90.432
one significant figure after decimal point
round off to 90.4
3.70
0.7867
two significant figures after decimal point
round off to 0.79

44. Significant Figures Multiplication or Division
The number of significant figures in the result is set by the original number that has the smallest number of significant figures
4.51 x =
= 16.5
3 sig figs
round to
3 sig figs
6.8 ÷ =
= 0.061
2 sig figs
round to
2 sig figs

45. Significant Figures Exact Numbers
Numbers from definitions or counted numbers of objects are considered to have an infinite number of significant figures
The average of three measured lengths; 6.64, 6.68 and 6.70? 3
= = 6.67
= 7
Because 3 is an exact number

46. Carry out the following arithmetic operations to the correct number of significant figures.
11,254.1 g g
66.59 L – L
8.16 m x
kg ÷ 88.3 mL
2.64x103 cm x102 cm

47. Carry out the following arithmetic operations to the correct number of significant figures.
9.1 g – g
7.1x104 dm x x102 dm
6.54 g ÷ mL
7.55x104 m – 8.62x103 m

48. Problem 1.36
Carry out the following operations as if they were calculations of experimental results, and express each answer in the correct units with the correct number of significant figures
7.310 km ÷ 5.70 km
(3.26 x 10-3 mg) – (7.88 x 10-5) mg
(4.02 x 106 dm) + (7.74 x 107 dm)
(7.8 m – 0.34 m)/(1.15 s s)

49. Accuracy – how close a measurement is to the true value
Precision – how close a set of measurements are to each other
accurate
&
precise
precise
but
not accurate
not accurate
&
not precise

50. Problem 1.38
Three apprentice tailors (X,Y, and Z) are assigned to the task of measuring the seam of a pair of trousers. The results in inches are: X (31.5, 31.6, 31.4) Y (32.8, 32.3, 32.7) Z (31.9, 32.2, 32.1) The true length is 32.0 in. Comment on the precision and accuracy of each tailor’s measurements.

51. Dimensional Analysis Method of Solving Problems
Determine which unit conversion factor(s) are needed
Carry units through calculation
If all units cancel except for the desired unit(s), then the problem was solved correctly.
given quantity x conversion factor = desired quantity
desired unit
given unit
given unit x
= desired unit

52. Dimensional Analysis Method of Solving Problems
How many mL are in 1.63 L?
Conversion Unit 1 L = 1000 mL 1L
1000 mL
1.63 L x
= 1630 mL 1L
1000 mL
1.63 L x = L2 mL

53. The speed of sound in air is about 343 m/s
The speed of sound in air is about 343 m/s. What is this speed in miles per hour?
conversion units
meters to miles
seconds to hours
1 mi = 1609 m
1 min = 60 s
1 hour = 60 min
343 m s x
1 mi
1609 m
60 s
1 min x
60 min
1 hour x
= 767 mi
hour

54. Problem 1.46
The current speed limit in some states in the US is 55 miles per hour. What is the speed limit in km/hr? (1 mi = 1609 m)

55. Problem 1.66
Vanillin is the substance whose aroma the human nose detects in the smallest amount. The threshold limit is 2.0 x 10-11g per liter of air. If the current price of 50 g of vanillin is $112, determine the cost (in cents) to supply enough vanillin so that the aroma could be detected in a large aircraft hanger with a volume of 5.0 x 107 ft3