Chemistry:
What are the branches of chemistry?
What are the five steps of the scientific method?
What is a problem? What is a
hypothesis? What types of Variables are used in an experiment?
Where are your variables located on a graph?
How do you make a conclusion? What is the difference between an observation and an inference?
Qualitative vs. Quantitative Law vs. Theory
Intro to Chemistry and Scientific
Method- Ch. 1
Study of the composition of matter and the changes that matter undergoes
Organic- the study of essentially all substances that contain carbon Inorganic- specializes primarily in substances that do not contain carbon Analytical- concerned with the composition of substances
Physical- studies theories and experiments that describe the behavior of chemicals Biochemistry- the study of the chemistry of living organisms
1. Problem 2. Hypothesis 3. Experiment
4. Observations and Data 5. Conclusion
Problem: What’s wrong?
Hypothesis: an educated guess, you predict what will happen based on prior knowledge
Independent Variable: What “I” change
Dependent Variable: What is measured/observed (Depends on the independent variable) Control Variables: Things kept the same during each experiment
Independent on the “X” axis Dependent on the “Y” axis
Your conclusion is based on your data and might support your hypothesis
Observation: the act of gathering information, one actually sees it Example: It is cloudy outside
Inference: an opinion based on observations
Example: Because it is cloudy outside one might say it is going to rain
Qualitative: Is the “quality,” it describes physical characteristics Quantitative: Is numerical, it describes something with numbers
Matter vs. Mass
A substance is?
What is a physical property?
What are examples of a physical property?
What the states of matter and give examples of each?
What is a physical Change and some examples?
What is a chemical change and signs of one occurring? What are the different types of mixtures and examples of each?
How many phases are in different types of mixtures?
What is one way that liquids can be separated from one another?
Matter and Change- Ch. 2
Matter: Anything that has mass and takes up space Mass: The amount of matter an object contains
Substance: matter that has uniform and definite composition Pure substances contain only one kind of matter
Physical property: is a quality or a condition of a substance that can be observed or measured without changing the substance’s composition.
• Color • Size • Hardness • Density • Shape
Solid: matter that has definite shape and volume. Ex: ice & pencil
Liquid: matter that has a fixed volume but takes the shape of it container. Ex: water & glue Gas: matter that takes both the shape and volume of its container. Ex: steam & helium
Physical change: Change in matter without changing the chemical composition.
Boiling Splitting Cracking Grinding
Cutting Crushing Bending Freezing
Melting Condensing Breaking
Chemical change: one or more substances changing into a new substance.
Bubbling Change in Temp
Color Change Change in Smell Mixture: a physical blend of two or more substances.
Heterogeneous: not uniform in composition Muddy Water
Chocolate-Chip Cookie Salad
Homogeneous: completely uniform in composition Milk
Salt water Solutions
Phase: any part of a system with uniform composition and properties. Heterogeneous mixtures: consist of two or more phases Homogenous mixtures: consist of one phase
Element vs. Compound
How to tell where to classify different types of matter
Compound Mixture or Element:
Explain the Law of Conservation of mass:
Matter and Change
Element: The simplest form of matter that can consist under normal laboratory conditions.
Aluminum (Al) Carbon (C) Mercury (Hg)
Compound: A substance that can be separated into simpler substances only by chemical means. Aluminum Chloride (AlCl3) Sodium Chloride (NaCl) Carbonic Acid (H2CO3)
1. Table sugar Compound
2. Water Compound
3. Iron Element
4. Vegetable Soup Mixture
5. Salt water Mixture
6. O2 Element
7. CaCO3 Compound
8. Air Mixture
Law of Conservation of Mass: Mass is neither created nor destroyed in chemical reactions
mass of reactants = mass of products
In a chemical reaction, the numbers and kinds of atoms present in the products are the same as those present in the reactants.
In a Chemical reaction two or more substances change into new substances. Reactants ® Products
Example:
Li + KCl ® LiCl + K Summary:
Matter
Substance Physically Separable
Compound Homogeneous Mixture Heterogeneous Mixture Mixture of Substances
Quantitative vs. Qualitative
Convert to
Scientific notation
Calculator practice
Accuracy vs. Precision
Percent Error Formula
What are the rules of determining SIG FIGS
How many SIG DIGS do you see?
Rounding Rules
Scientific Measurement- Ch. 3
Qualitative: observation
Quantitative: numerical
241 = 2.41 x 102
6015 = 6.015 x 103
0.0162 = 1.62 x 10-2
0.512 = 5.12 x 10-1
6.62 x 102 = 662
3.4 x 10-3 = 0.0034
6.25 x 103 - 2.01 x 102 = 6.05 x 103 (2.15 x 103)(6.1 x 105)(5.0 x 10-6) =
6.6 x 103
3.25 x 10 = 9.0 8
3.6 x 107
Accuracy: the measure of how close a measurement comes to the actual or true value of whatever is measured.
Precision : the measure of how close a series of measurements are to one another.
% Error = accepted value- experimental value x 100 accepted value
1. All non-zero digits are significant.
2. Zeros between non-zero digits are significant. (AKA captive zeros)
3. Leading zeros (zeros at the beginning of a measurement) are NEVER significant.
4. Trailing zeros (zeros after last integer) are significant only if the number contains a decimal point.
5. All digits are significant in scientific notation.
Exact numbers have unlimited Significant Figures
a) 1.2 (2) d) 4600 (2)
b) 2.0 (2) e) 23.450 (5)
c) 3.002 (4) f) 6.02 x 1023 (3)
Rounding Rules:
Number of Sig Digs when adding/ subtracting
Number of Sig Digs when Multiplying/Dividing
When in lab, how do we measure sig digs?
International System of Units
What are the variables used in Density?
Formula:
Temperature
Conversion:
Scientific Measurement
The measurement with the fewest significant figures to the right of the decimal point determines the number of significant figures in the answer.
45.756 m + 62.1 m = 107.9 m 75.263 m + 1123.93 m = 1199.19 m
The measurement with the fewest significant figures determines the number of significant figures in the answer.
3.43 m X 6.4253 m = 22.0 m 45.756 m X 1.2 m = 55 m 45.01 m / 2.2 m = 99 m
In lab, you record all numbers you know for sure plus the first uncertain digit. The last digit is estimated and is said to be uncertain but still considered significant.
Graduated cylinders have markings to the nearest mL (milliliter) and you will determine volume to the nearest 0.1 mL because that is ONE DIGIT OF UNCERTAINTY.
revised version of the metric system abbreviated SI
Meter (m) – Liter (L) – Gram (g) –
Mass – (g) amount of matter in an object
Volume – (mL) amount of space occupied by an object Density – (g/mL) a ratio of mass to volume
D = M V
A piece of metal has a volume of 4.70 mL and a mass of 57.3 g. What is the density?
measurement of the average kinetic energy of a system.
Celsius : Sets the freezing point of water at 0°C and the boiling point at 100°C
Kelvin : Absolute zero is set as the zero on the Kelvin scale. It is the temperature at which all motion theoretically ceases.
K = ºC + 273 -273 º C = 0 K = absolute zero
