Chap1 Chang

8/10/2019 Chap1 Chang

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Chemistry:

The Study of Change

Chapter 1

Copyright The McGraw-Hill Companies, Inc !ermission re"uired for reproduction or display

PowerPoint Lecture Presentation

by

J. David Robertson

University of Missouri


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Chemistry: # Science for the $%stCentury

&Health and Medicine

&Sanitation systems

&Surgery with anesthesia

&'accines and anti(iotics

&)nergy and the )n*ironment

&+ossil fuels

&Solar energy

&uclear energy

%%


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Chemistry: # Science for the $%stCentury

&Materials and Technology

&!olymers, ceramics, li"uid crystals

&oom-temperature superconductors.

&Molecular computing.

&+ood and #griculture

&Genetically modified crops

&/atural0 pesticides

&Speciali1ed fertili1ers

%%


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The scientific methodis a systematic

approach to research

%2

# lawis a concise statement of a relationship

(etween phenomena that is always the same

under the same conditions

# hypothesis is a tentati*e e3planation for aset of o(ser*ations

tested modified


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CHEMISTRY

The study of MATTER and the

changes that matter undergoes

and the energyassociated with

the changes.

MATTER is anything thatoccupies space and has mass.


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% Matteris anything that occupies space and

has mass

$ # substanceis a form of matter that has a

definite composition and distinct properties

Chemistryis the study of matter and the

changes it undergoes

water, ammonia, sucrose, gold, o3ygen

%4


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#compoundis a su(stance composed of atoms of two or

more elements chemically united in fi3ed proportions

Compounds can only (e separated into their pure

components 5elements6 (y chemical means 5e3ample:

decomposition,electrolysis6

Water (H2O) Glucose (C6H12O6)

Ammonia (H!)

%4

"ure su#stance- Homogeneous matter with a definite, or

fi3ed, composition


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#n elementis a su(stance that cannot(e

separated into simpler su(stances (y chemical

means.

&%%2 elements ha*e (een identified

&7$ elements occur naturally on )arth

gold, aluminum, lead, o3ygen, car(on

&2% elements ha*e (een created (y scientists

technetium, americium, sea(orgium

%4


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# mixtureis a com(ination of two or more su(stances

in which the su(stances retain their distinct identities

% Homogenous mixture8 composition of the

mi3ture is the same throughout

$ Heterogeneous mixture8 composition is not

uniform throughout

soft drin9, mil9, solder

cement,

iron filings in sand

%4


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Mi$tures

Heterogeneous mixtures : has one or more visible

boundaries between the components.

Homogeneous mixtures :has no visible boundaries

because the components are mixed as individual atoms,

ions, and molecules.

Solutions : A homogeneous mixture is also called a solution.

Solutions in water are called aqueous solutions, and are very important in chemistry. Although we normally thin

o! solutions as li"uids, they can exist in all three physical

states.


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Se%aratin& Mi$tures

Filtration : Separates components o! a mixture based upon

differences in particle size.#ormally separating a

precipitate !rom a solution, or particles !rom an

air stream.

rystalli!ation : Separation is based upon differences in

solubilityo! components in a mixture.

"istillation :separation is based upon differences in volatility.

Extraction :Separation is based upon differences insolubility in di!!erent solvents $ma%or material&.

hromatography : Separation is based upon differences

in solubility in a solvent versus a stationary phase.


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Physical meanscan #e use' to se%arate a

mi$ture into its %ure com%onents

magnet

%4

distillation


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i& 2*

iltration


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Cr+stalli,ation

i& 2E


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i& 2


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i& 2G


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"roce'ure -or Column C.romato&ra%.+

i& 2H


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/0ESTIO 1

Classi-+ eac. o- t.e -ollo3in& as 4element5

4com%oun'5 4.omo&enous mi$ture5 or.etero&enous mi$ture

(a) Sil7er

(#) Et.+l alco.ol

Ans Element

Ans Com%oun'

(c) Ta#le salt Ans Com%oun'

(') C.ocolate c.i% coo8ies Ans Hetero&enousmi$ture

(e) Su&ar 'issol7e' in 3ater Ans Homo&enousmi$ture


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%4


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T.ree States o- Matter

%

solidli"uid

gas


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T.e T.ree States o- Matter


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".+sical C.an&e or C.emical C.an&e9

#physical changedoes not alter the composition or

identity of a su(stance

# chemical changealters the composition oridentity of the su(stance5s6 in*ol*ed

ice meltingsugar dissol*ing

in water

%;

hydrogen (urns in

air to form water


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An extensive property o- a material 'e%en's

u%on .o3 muc. matteris is #ein& consi'ere'

An intensive property o- a material 'oes not

'e%en'u%on .o3 muc. matter is is #ein&

consi'ere'

&mass

&len&t.

&7olume

&'ensit+

&tem%erature

&color

E$tensi7e an' Intensi7e "ro%erties

%;


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Matter - anything that occupies space and has mass

mass8 measure of the "uantity of matter

SI unit of mass is the kilogram59g6

% 9g < %=== g < % 3 %=2g

weight8 force that gra*ity e3erts on an o(>ect

weight < c3 mass

on earth, c< %=

on moon, c? =%

%@

# % 9g (ar will weigh

% 9g on earth

=% 9g on moon


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%@


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%@


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Volume8 SI deri*ed unit for *olume is cu(ic meter 5m26

% cm2< 5% 3 %=-$m62< % 3 %=-;m2

% dm2< 5% 3 %=-%m62< % 3 %=-2m2

% A < %=== mA < %=== cm2< % dm2

% mA < % cm2

%@


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Density8 SI deri*ed unit for density is 9gBm2

% gBcm2< % gBmA < %=== 9gBm2

density ects are consideredto ha*e an infinite num(er of significant figures

The a*erage of three measured lengths ;;4, ;;7 and ;@=.

;;4 F ;;7 F ;@=

2< ;;@222 < ;;@

Jecause 2 is an e3act num(er

< @


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Accuracy8 how close a measurement is to the true*alue

Precision8 how close a set of measurements are to each other

accurate

K

precise

precise

(ut

notaccurate

notaccurate

K

notprecise

%7

*i i l A l i M t. ' ( t # l M t. ')


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%

*imensional Anal+sis Met.o' (actor a#el Met.o')

o- Sol7in& "ro#lems

% etermine which unit con*ersion factor5s6 are needed

$ Carry units through calculation

2 If all units cancel e3cept for the desired unit5s6, then the

pro(lem was sol*ed correctly

% A < %=== mA

How many mA are in %;2 A.

%A

%=== mA%;2 A 3

< %;2= mA

%A

%=== mA

%;2 A 3 < ===%;2=A$

mA


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T.e s%ee' o- soun' in air is a#out !=! mDs W.at

is t.is s%ee' in miles %er .our9

1 mile 16;< m 1 min 6; s 1 .our 6; min

!=!ms

$1 mile

16;< m

6; s

1 min

$6; min

1 .our

$ 6mile

.our

meters to milessecon's to .ours

%

/uestion 1


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/uestion 1

Calculate the mass of $== ft2of lead, gi*en density

of lead is %%4 gBmA

5% ft < %$ inches % inch < $4 cm6

#nswer:

$== ft2 L%$ inches

% ft

2

L$4 cm

% inch

2

'olume

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Chap1 Chang