ChemistryChemistry

1.B Fundamental 1.B Fundamental Quantitative Quantitative RelationshipsRelationships

Significant Digits Significant Digits 1. All numbers 1-9 are significant1. All numbers 1-9 are significant 235 = 3 significant figures235 = 3 significant figures 132.24 = 5 significant figures132.24 = 5 significant figures 2. Leading zeros are not significant2. Leading zeros are not significant .009 = 1 significant figure.009 = 1 significant figure 3. Captive zeros are significant3. Captive zeros are significant

5005 = 4 significant figures5005 = 4 significant figures 4. Trailing zeros are significant if the 4. Trailing zeros are significant if the

number contains a decimal pointnumber contains a decimal point157.00 = 5 significant figures.157.00 = 5 significant figures.

Significant Figures in Addition Significant Figures in Addition and Subtractionand Subtraction

The number of decimal places in the The number of decimal places in the result is the same as the least result is the same as the least number of decimal places used in the number of decimal places used in the calculationcalculation

12.33 + 2.1 + 3.087 = ?12.33 + 2.1 + 3.087 = ?

Significant Figures in Significant Figures in Multiplication and DivisionMultiplication and Division

The number of significant figures in The number of significant figures in the result is the same as the least the result is the same as the least number of significant figures used in number of significant figures used in the calculation. the calculation.

5.65 X 1.3 = ?5.65 X 1.3 = ?

When Both Exist When Both Exist

If you are working a problem that has If you are working a problem that has multiplication, division, addition, and multiplication, division, addition, and subtraction, then you must use your subtraction, then you must use your order of operations. PEMDASorder of operations. PEMDAS

Practice: 3.43 X 2.36 + 4 = Practice: 3.43 X 2.36 + 4 =

SI Base UnitsSI Base Units There are seven SI base units. There are seven SI base units. Quantity symbol name abbreviationQuantity symbol name abbreviation

1. length l meter m1. length l meter m2. mass m gram g2. mass m gram g3. time t second s3. time t second s4. temperature T kelvin K 4. temperature T kelvin K 5. amount of 5. amount of

a substance n mole mola substance n mole mol 6. electric6. electric current I ampere Acurrent I ampere A 7. luminous7. luminous intensity Iintensity Ivv candela cd candela cd

Metric System and PrefixesMetric System and Prefixes

King Henry died by drinking chocolate milk. King Henry died by drinking chocolate milk. k h da k h da BB d c m d c m

101033 10 1022 10 1011 10 10-1-1 10 10-2-2 10 10-3-3

B = Base Unit (gram) (Liter) (meter)B = Base Unit (gram) (Liter) (meter)

Derived Units are any unit that uses a prefix. Derived Units are any unit that uses a prefix. (centimeter)(centimeter)

k = kilo h = hecto da = dekak = kilo h = hecto da = deka

d = deci c = centi m = millid = deci c = centi m = milli

Metric ConversionsMetric Conversions

1 kg = ? g1 kg = ? g .3 m = ? cm.3 m = ? cm 100 kL = ? L100 kL = ? L .3g = ? hg.3g = ? hg 12mL = ? kL12mL = ? kL 12g = ? mg12g = ? mg 100 kL = ? hL100 kL = ? hL

Derived UnitsDerived Units

Derived units are formed from the Derived units are formed from the combination of SI base unitscombination of SI base units

Area = mArea = m22

Volume = mVolume = m33

Density = kg/mDensity = kg/m33

Metric Volume ConversionsMetric Volume Conversions

Volume = length X width X height Volume = length X width X height (these are all a measure of length (these are all a measure of length which would be in centimeters)which would be in centimeters)

Our volume conversion factor is Our volume conversion factor is

1 cm1 cm33 = 1 mL = 1 mL 34.3 L = ? m34.3 L = ? m33

3.8 mm3.8 mm33 = ? mL = ? mL

Scientific NotationScientific Notation

Any number 1000 or above needs to Any number 1000 or above needs to be written in scientific notation. be written in scientific notation.

23,000 = 2.3 X 1023,000 = 2.3 X 1044

Any number at .001 or less needs to Any number at .001 or less needs to be written in scientific notation.be written in scientific notation.

.00786 = 7.86 X 10.00786 = 7.86 X 10-3-3

DensityDensity

Density = Density = massmass

volumevolume

What is the density of a 19.625g object What is the density of a 19.625g object with a volume of 25.00 cmwith a volume of 25.00 cm33??

Problem Solving Problem Solving

If water has a density of 1g/mL, what If water has a density of 1g/mL, what is the mass of 150 mL of water?is the mass of 150 mL of water?

Kool-aid is approximately 39% sugar. Kool-aid is approximately 39% sugar. If the kool-aid has a density of If the kool-aid has a density of 4.5g/mL, determine the grams of 4.5g/mL, determine the grams of sugar in 300.0mL of kool-aid?sugar in 300.0mL of kool-aid?

Temperature ConversionsTemperature Conversions

TTK K = temperature in Kelvin= temperature in Kelvin

TTCC = temperature in Celsius = temperature in Celsius

TTFF = temperature in Fahrenheit = temperature in Fahrenheit

TTC C = (T= (TF F – 32) / 1.8– 32) / 1.8

TTF F = T= TCC (1.8) + 32 (1.8) + 32

TTK K = T= TC C + 273+ 273

TTC C = T= TK K - 273- 273

Temperature ConversionsTemperature Conversions

1. 67.°F = ? K 1. 67.°F = ? K 2. 340.K = ? °C2. 340.K = ? °C 3. 46.°C = ? °F3. 46.°C = ? °F 4. 587. K = ? °F4. 587. K = ? °F 5. 87.°F = ? °C5. 87.°F = ? °C

Accuracy and PrecisionAccuracy and Precision

Accuracy = correctness; agreement Accuracy = correctness; agreement of a measurement with the true of a measurement with the true valuevalue

Precision = reproducibility; degree of Precision = reproducibility; degree of agreement among several agreement among several measurements.measurements.

Dimensional AnalysisDimensional Analysis

A A literal equationliteral equation is one which is is one which is expressed in terms of variable expressed in terms of variable symbols (such as d, v, and a) and symbols (such as d, v, and a) and constants (such as g). Often in constants (such as g). Often in science and math you are given an science and math you are given an equation and asked to solve it for a equation and asked to solve it for a particular variable symbol or letter particular variable symbol or letter called called an unknownan unknown..

Dimensional AnalysisDimensional Analysis

F = ma solve for aF = ma solve for a v = d/t solve for tv = d/t solve for t ab = cd solve for cab = cd solve for c R = dh/a solve for dR = dh/a solve for d A = h(a+b) solve for bA = h(a+b) solve for b

Scientific MethodScientific Method

The scientific method is a logical The scientific method is a logical approach to solving problems by approach to solving problems by observing and collecting data, observing and collecting data, formulating hypothesis, and formulating hypothesis, and formulating theories that are formulating theories that are supported by data.supported by data.

Observing and Collecting Observing and Collecting DataData

Observing is the use of the senses to Observing is the use of the senses to obtain information. Observation often obtain information. Observation often involves making measurements and involves making measurements and collecting data.collecting data.

That data may be descriptive That data may be descriptive (qualitative) or numerical (qualitative) or numerical (quantitative) in nature.(quantitative) in nature.

SystemsSystems

Experimenting involves carrying out a Experimenting involves carrying out a procedure under controlled conditions to make procedure under controlled conditions to make observations and collect data. To learn more observations and collect data. To learn more about matter, chemist study systems. about matter, chemist study systems.

A system is a specific portion of matter in a A system is a specific portion of matter in a given region of space that has been selected given region of space that has been selected for study during an experiment or observation. for study during an experiment or observation.

When you observe a reaction in a test tube, When you observe a reaction in a test tube, the test tube and its contents form a system.the test tube and its contents form a system.

Forming HypothesisForming Hypothesis As scientists examine and compare the data As scientists examine and compare the data

from their own experiments, they attempt to from their own experiments, they attempt to find relationships and patterns – in other find relationships and patterns – in other words, they make generalizations based on words, they make generalizations based on the data.the data.

Scientists use generalizations about the data Scientists use generalizations about the data to formulate a hypothesis, or testable to formulate a hypothesis, or testable statement. statement.

The hypothesis serves as the basis for The hypothesis serves as the basis for making predications and for carrying out making predications and for carrying out further experiments. further experiments.

Hypothesis are often drafter as “if-then” Hypothesis are often drafter as “if-then” statements. The “then” part of the statements. The “then” part of the hypothesis is a prediction that is the basis for hypothesis is a prediction that is the basis for testing by experiment. testing by experiment.

Testing HypothesisTesting Hypothesis

Testing a hypothesis requires Testing a hypothesis requires experimentation that provided data to experimentation that provided data to support or refute a hypothesis or theory.support or refute a hypothesis or theory.

During testing, the experimental conditions During testing, the experimental conditions that remain constant are called controls and that remain constant are called controls and any condition that changes is called a any condition that changes is called a variable. variable.

If testing reveals that the predictions were not If testing reveals that the predictions were not correct, the hypothesis on which the correct, the hypothesis on which the predictions were based must be discarded or predictions were based must be discarded or modified. modified.

TheorizingTheorizing

When the data from experiments show that When the data from experiments show that the predictions of the hypothesis are the predictions of the hypothesis are successful, scientists typically try to explain successful, scientists typically try to explain the phenomena they are studying by the phenomena they are studying by constructing a model. constructing a model.

A model in science is more than a physical A model in science is more than a physical object, it is often an explanation of how object, it is often an explanation of how phenomena occur and how data and events phenomena occur and how data and events are related. are related.

Models may be visual, verbal, or Models may be visual, verbal, or mathematicalmathematical

TheoryTheory

A theory is a broad generalization A theory is a broad generalization that explains a body of facts or that explains a body of facts or phenomena. phenomena.

Theories are considered successful if Theories are considered successful if they can predict the results of many they can predict the results of many new experiments.new experiments.

Experiments Involve Two Experiments Involve Two GroupsGroups

ControlControl – part of an experiment that – part of an experiment that is the standard against which results is the standard against which results are compared.are compared.

Receives no experimental treatment. Receives no experimental treatment. Testing fertilizer:Testing fertilizer:The plant without the fertilizer would The plant without the fertilizer would

be the control because you would be the control because you would compare the plant that was fertilized compare the plant that was fertilized with the one without it.with the one without it.

VariablesVariables

Variable is what you change in an Variable is what you change in an experiment.experiment.

In a controlled experiment only one In a controlled experiment only one condition is changed at a time. condition is changed at a time.

2 types of variable2 types of variable

Independent VariablesIndependent Variables

Dependent VariablesDependent Variables

Independent VariableIndependent Variable

The condition in an experiment that The condition in an experiment that is tested. is tested.

The only factor that affects the The only factor that affects the outcome of the experiment.outcome of the experiment.

In the case of using fertilizer, the In the case of using fertilizer, the presence of fertilizer is the presence of fertilizer is the independent variable.independent variable.

Dependent VariableDependent Variable

The Dependent variable depends on The Dependent variable depends on the affects of the independent the affects of the independent variable. variable.

Fertilizer: The growth of the plant Fertilizer: The growth of the plant would be the dependent variable would be the dependent variable because the fertilizer (independent because the fertilizer (independent variable) caused the change.variable) caused the change.

Dependent variables are graphed on the y-Dependent variables are graphed on the y-axisaxis

Independent variables are graphed on the Independent variables are graphed on the x axis x axis