chapter 1 lesson 1 chem 105 kristen kull sims 115 kristen kull kristen kull chem105 general...

Chapter 1 Lesson 1Chapter 1 Lesson 1

Chem 105 Chem 105 Kristen KullKristen KullSIMS 115SIMS 115

Kristen KullKristen Kull

CHEM105 General Chemistry I (Kull)CHEM105 General Chemistry I (Kull)

Course InformationCourse Information

Course ScheduleCourse Schedule

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Chapter 1 Chapter 1 Matter and Measurement

1.1 Classifying matter1.1 Classifying matter

Matter consists of atoms and molecules in motionMatter consists of atoms and molecules in motion


STATES OF MATTERSTATES OF MATTERSTATES OF MATTERSTATES OF MATTER SOLIDSSOLIDS — have rigid shape, fixed volume. — have rigid shape, fixed volume.

External shape can reflect the atomic and External shape can reflect the atomic and molecular arrangement.molecular arrangement.– Reasonably well understood.Reasonably well understood.

LIQUIDSLIQUIDS — have no fixed shape and may not fill — have no fixed shape and may not fill a container completely. a container completely. – Not well understood.Not well understood.

GASESGASES — expand to fill their container. — expand to fill their container. – Good theoretical understanding.Good theoretical understanding.


1.2 Elements and atoms1.2 Elements and atoms Periodic table – names, symbols, massesPeriodic table – names, symbols, masses ofof CHEMICAL ELEMENTSCHEMICAL ELEMENTS - -

– pure substances that cannot be pure substances that cannot be decomposed by ordinary means to other decomposed by ordinary means to other substances.substances.

An An atomatom is the smallest particle of an element is the smallest particle of an element that has the chemical properties of the that has the chemical properties of the element.element.

An An atomatom consists of a consists of a nucleusnucleus

(of (of protonsprotons and and neutronsneutrons) and ) and

electronselectrons in space about the in space about the

nucleus.nucleus.


1.3 Compounds and 1.3 Compounds and MoleculesMolecules

CompoundCompound – two or more different elements – two or more different elements When elements are part of a compound, When elements are part of a compound,

original properties are replaced by original properties are replaced by characteristic propertiescharacteristic properties

AA MOLECULEMOLECULE is the smallest unit of a is the smallest unit of a compound that retains the chemical compound that retains the chemical characteristics of the compound.characteristics of the compound.


1.4 Physical properties1.4 Physical properties Properties which can be Properties which can be measured measured

without changing the compositionwithout changing the composition of of the substancethe substance

Chemists are interested Chemists are interested

in the nature of matter in the nature of matter

and how this is related and how this is related

to its atoms and molecules.to its atoms and molecules. Graphite:Graphite: layer structure layer structure

of carbon atoms reflects of carbon atoms reflects

physical properties.physical properties.


Physical PropertiesPhysical Properties--colorcolor-melting and -melting and boiling pointboiling point-odor-odor

Physical ChangesPhysical Changes boiling of a liquidboiling of a liquid melting of a solidmelting of a solid dissolving a solid in a dissolving a solid in a

liquid to give a homogeneous liquid to give a homogeneous

mixture — a SOLUTION.mixture — a SOLUTION.


Intensive property – not dependent on quantity Intensive property – not dependent on quantity (density)(density)

Extensive property – varies with quantity (mass)Extensive property – varies with quantity (mass)


DENSITYDENSITY - an - an important and useful important and useful physical propertyphysical property

Density mass (g)volume (cm3)


Mercury

13.6 g/cm13.6 g/cm33 21.5 g/cm21.5 g/cm33

Aluminum

2.7 g/cm2.7 g/cm33

Platinum


ProblemProblem A piece of copper has a A piece of copper has a mass of 57.54 g. It is 9.36 cm mass of 57.54 g. It is 9.36 cm long, 7.23 cm wide, and 0.95 mm long, 7.23 cm wide, and 0.95 mm thick. Calculate density (g/cmthick. Calculate density (g/cm33).).




StrategyStrategy1. Get dimensions in common 1. Get dimensions in common

units.units.

2.2. Calculate volume in cubic Calculate volume in cubic centimeters.centimeters.

3. Calculate the density.3. Calculate the density.


SOLUTIONSOLUTION1. Get dimensions in common 1. Get dimensions in common

units.units.

2.2. Calculate volume in cubic Calculate volume in cubic centimeters.centimeters.

3. Calculate the density.3. Calculate the density.

0.95 mm • 1cm

10 mm = 0.095 cm

57.54 g

6.4 cm3 = 9.0 g / cm3

(9.36 cm)(7.23 cm)(0.095 cm) = 6.4 cm(9.36 cm)(7.23 cm)(0.095 cm) = 6.4 cm33

Note only 2 significant figures in the answer!Note only 2 significant figures in the answer!


PROBLEM: Mercury (Hg) has a PROBLEM: Mercury (Hg) has a density of 13.6 g/cmdensity of 13.6 g/cm33. What is . What is the mass of 95 mL of Hg in the mass of 95 mL of Hg in grams? In pounds?grams? In pounds?

PROBLEM: Mercury (Hg) has a PROBLEM: Mercury (Hg) has a density of 13.6 g/cmdensity of 13.6 g/cm33. What is . What is the mass of 95 mL of Hg in the mass of 95 mL of Hg in grams? In pounds?grams? In pounds?

Solve the problem using Solve the problem using DIMENSIONAL DIMENSIONAL ANALYSIS.ANALYSIS.


StrategyStrategy

1.1. Use density to calc. mass (g) from Use density to calc. mass (g) from volume.volume.

2.2. Convert mass (g) to mass (lb)Convert mass (g) to mass (lb)

Need to know conversion factorNeed to know conversion factor

= 454 g / 1 lb= 454 g / 1 lb

PROBLEM: Mercury (Hg) has a PROBLEM: Mercury (Hg) has a density of 13.6 g/cmdensity of 13.6 g/cm33. What is . What is the mass of 95 mL of Hg?the mass of 95 mL of Hg?


First, note that First, note that 1 cm1 cm33 = 1 mL = 1 mL


1.1. Convert volume to Convert volume to massmass



1.3 x 103 g • 1 lb

454 g = 2.8 lb

2.2. Convert mass (g) to mass (lb)Convert mass (g) to mass (lb)

( 95 cm3 )(13.6 g/cm3) = 1.3 x 103 g


1.5 Physical and Chemical 1.5 Physical and Chemical changeschanges

Physical change: identity is Physical change: identity is preserved; not always the state preserved; not always the state (melting point)(melting point)

Chemical change: new substances Chemical change: new substances are producedare produced


1.6 Units of Measurement1.6 Units of Measurement

Qualitative: no measurements or Qualitative: no measurements or numbers involved ex. color numbers involved ex. color (observations)(observations)

Quantitative: numerical information Quantitative: numerical information ex. Time, mass, volumeex. Time, mass, volume– Metric (SI) base units Table 1.2, page 26Metric (SI) base units Table 1.2, page 26– Selected prefixes used in the metric Selected prefixes used in the metric

system, Table 1.3, page 27system, Table 1.3, page 27


Temperature ScalesTemperature Scales

Notice that 1 kelvin degree = 1 degree Celsius1 kelvin degree = 1 degree Celsius

Boiling point Boiling point of waterof water

Freezing point Freezing point of waterof water

CelsiusCelsius

100 ˚C100 ˚C

0 ˚C0 ˚C

100˚C100˚C

KelvinKelvin

373 K373 K

273 K273 K

100 K100 K

FahrenheitFahrenheit

32 ˚F32 ˚F

212 ˚F212 ˚F

180˚F180˚F

•T (˚C)T (˚C) = 5/9 [T(˚F) – 32](˚F) – 32]

• T (K) = t (˚C) + 273.15T (K) = t (˚C) + 273.15


1.7 Making measurements1.7 Making measurements Precision: how well Precision: how well

several values several values agreeagree

Standard deviationStandard deviation

Accuracy: how close Accuracy: how close to the accepted to the accepted valuevalue

Percent errorPercent error


1.8 Mathematics of 1.8 Mathematics of ChemistryChemistry

Exponential or scientific notationExponential or scientific notation– No more significant than least No more significant than least

significantsignificant Dimensional AnalysisDimensional Analysis

– Always write your units; one will always Always write your units; one will always cancel outcancel out

chapter 1 lesson 1 chem 105 kristen kull sims 115 kristen kull kristen kull chem105 general...

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