Download presentation
Presentation is loading. Please wait.
Published byAlan Robertson Modified over 8 years ago
1
Chapter 1 and 2 Introduction to Chemistry
2
Quantitative vs Qualitative Quantitative – Measurements – Ex. 23 m, :46 s, 3.5 kg Qualitative – Observations – Deals with senses – Ex. Yellow, bitter, loud
3
Graphs and Charts – Pie Charts % or part of a whole
4
Graphs and Charts – Bar Graph Quantity over varied locations
5
Graphs and Charts – Line Graph Shows a relationship or trend of data Variable on the x- axis is the independent variable Variable on the y- axis is the dependent variable
6
Graphs and Charts – Line Graph Line of best fit – The line follows the overall movement of points – Use a straight edge
7
Theories and Laws Do theories become laws? Is a theory like a hypothesis?
8
Theories and Laws Theory – A true statement based upon facts and data that we have now. – Ex. Theory of Evolution Can a theory change? – Yes, theories can be modified when we get additional data or observations. Law – based on observable fact. – Theories can be used to explain laws. – Does not change. – Ex. Law of gravity
9
Pure Research vs Applied Research Pure research – Purely for gaining knowledge Applied research – Uses knowledge to solve a problem Ex. A chemist and a chemical engineer
10
SI Unit Standard International Unit How is it different from units that we use like feet or pounds? – Why is it important? Digits 0-10 Place 1-10-100-1000… Ex. 12 – I have 1 group of 10 and 2 groups of 1
11
2 Types of Units Base – Defined unit of measurement – Time (s), length(m), and mass (kg) Derived – What does derived mean? – Comes from a combination of base units – Mph, g/ml, g/cm3
12
SI Base Units Time – s Length – m Mass - kg
13
Density – A Derived Unit What is the formula for density? – D = m/v Ex. 5.2 g occupy 15.6 mL – 5.2 g / 15.6 ml =.333 g /mL
14
Units of Measurement 231 What does this mean? – 231 lbs, 231 cm, 231 g Unit of measurement is important. Make sure you include this.
15
Pg. 26 10 -2 = centi We will not use negative exponents for this 1 m = 10 2 cm
16
1 Mm = 10 6 m 1km = 10 3 m 1 m = 10 dm 1 m = 10 2 cm 1m= 10 3 mm 1m = 10 6 µm 1 m = 10 9 nm 1m = 10 12 pm 1 ML = 10 6 L 1kL = 10 3 L 1 L = 10 dL 1 L = 10 2 cL 1L= 10 3 mL 1L = 10 6 µL 1 L = 10 9 nL 1L = 10 12 pL
17
Mass Conversions You should see the relationship among the prefixes.
18
Test Taking Strategy Write down prefixes with conversions somewhere on the test.
19
1 mL = 1 cm 3
20
Conversion problems – Pg.34 #17
22
Group work Pg 34 #18
23
Temperature What does temperature actually measure? – Heat or amount of energy We will use Celsius and Kelvin What temperature does water freeze and boil? Can you go below 0 0 C? – Liquid nitrogen is -196 0 C – Dry ice is -78.5 0 C Can liquid water ever go above 100 0 C?
24
The Kelvin Scale What is freezing point of water on the Kelvin scale? – 273 K What is 0 K? – Absolute 0 – This is as cold as it gets
25
Scientific Notation N x 10 n What part is the number? All of it 1 < m < 10 Precision 0.23451 is more precise than 0.2 N (integer)Magnitude (exponent) The greater the exponent the larger the magnitude +N(exponent)Larger -N(exponent)Smaller
26
Scientific Notation 4231.3 – 4.2313 x 10 3 0.002179 – 2.179 x 10 -3 0.012 x 10 -1 – 1.2 x 10 -3 300 x 10 2 – 3 x 10 4 1000 x 10 -2 – 1 x 10 The number you end with must have the same value as the number you start with.
27
Scientific Notation Problems – Pg. 32 – #13 Group Work – #12
28
Data Analysis Interpolating Data – Data that comes from points on the line – Between extreme measured points Extrapolating Data – Uses the trend of a line to make a prediction – Does not come from measured points
29
Accuracy vs Precision Accuracy – Closeness to accepted value Precision – Reproducing a given measurement
30
Calculator Texas Instrument Programmable (Graphing)
31
Assign Calculators and Rules You will get your calculator everyday unless I tell you otherwise. Put your calculator number in your book by your name. Calculators are around $100.00. Do not use anything other than you fingers to touch the calculator. No pens or pencils. Do not pick on the black rubber pieces on the back of the calculator. Do not mess with the batteries or the battery door. I need to know if your number is missing.
32
Percent Error
33
Percent Error Problems – Pg. 38 – #29 Group Work #30 Metric Conversions w/ scientific notation
34
Practice Problems 1.507 cL to L 2.0.057 m to km 3.13 cm 3 to mL 4.56 km to mm 5.29 kg to cg 6.25 kg/cL to g/L 7.1.352 km/h to m/s 8.2. 14 minutes to seconds 9.1.2 x 10 3 m to km 10.3.49x10 -6 g to ng
36
Homework Page 50 72-75, 80, 82, 86
37
Homework Review
38
Significant Digits Do this on your calculator. 2300 + 1200 What do you get? Are all of these numbers significant?
39
Significant Digit Rules 1.Non zero digits are significant 2.Embedded zeros are significant – What does embedded mean? 3.Placeholding zeros are not significant 4.Trailing zeros to the right of an explicit decimal are significant. – What is an explicit decimal? What is an implied decimal? 5.Counting numbers and constants never determine significance.
40
Significant Digit Rules Ex. Rule 1: All non zero digits are significant. How many significant digits are in: – 42.14 – 92.35 – 2.1497421
41
Significant Digit Rules Ex. Rule 2: Embedded zeros are significant. How many significant digits are in: – 2.1505 – 304210.401 – 42.000005
42
Significant Digit Rules Ex. Rule 3: Placeholding zeros are never significant. How many significant digits are in: – 3100 – 40 – 0.00032485
43
Significant Digit Rules Ex. Rule 4:Trailing zeros to the right of an explicit decimal are significant. 560 and 560.0 What’s the difference? – 560 can be in the range of 555-564 – 560.0 can be in the range of 559.95-560.04
44
Rule 4 continued How many significant digits are in: 0.0500 400.0 10000.0 0.000540
45
Significant Digit Rules Ex. Rule 5: Counting numbers and constants will never determine significance. – Avogadro’s constant - 6.023x10 23 – 6 molecules Numbers such as these would not be used to calculate the number of significant digits in your answer.
46
Calculations Using Significant Digits In your calculations you will use the least amount of significant digits for multiplication and division. – In the problem 3829 x 8100, what is the least amount of significant digits? – That is the one you will use in your answer. For addition and subtraction, you will round to the least place. – 34.56 + 9.2, what is the least place? – That is the place you will use in your answer
47
Addition and Subtraction 3.215 + 2.5 410 + 321.5721 821 – 1.7623
48
Multiply and Divide 4.213 x 1.5 6.72 x 3.3419 3.75 / 1.223
49
Significant Digits Practice Give the number of significant digits for the following. 401.2 300 50421.001 0.0200 3.1 x 10 -2 3.0023 x 10 5 5.7010 x 10 12
50
Understand? If you grasp the idea of significant digits then answer this. Write 100 with 2 significant digits.
51
Entering Exponents into Your Calculator 2.4315 x 10 2 You will enter 2.4315 then EE 2 Your answers will also show up in this format
52
Dimensional Analysis / Unit Conversion / Factor Label When adding and subtracting the units will remain the same. When multiplying the units will become squared. When dividing the units will cancel. You will always round to significant digits but the magnitude must remain the same. – Your answer is 4800 and must have 2 significant digits. – You would not put 4.8. The answer would be 4.8 x 10 3
53
Rules for Exponents X n x X m = X n+m X n / X m = X n-m (X n ) m = X n x m 1 / X n = X -n
54
Converting Squared or Cubed Units cm 3 is the same as cm x cm x cm Example: 3.6 m 3 mm 3 3.6 m 3 x 10 3 mm x 10 3 mm x 10 3 mm 1 m 1 m 1 m Answer: 3.6 x 10 9 mm 3
55
Practice Problems 360s ms 4800g kg 25 kg µg 2.5 x 10 -3 µm pm 12.2 g/mL Kg/L 3.9 m 3 nm 3 89.5 pm 2 m 2
56
Homework Pg. 51 # 77-78 and 83-85 Pg. 871 # 6
57
Homework Review
58
Chapter 2 Test Review
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.