chapter 1 study of change

7/18/2019 Chapter 1 Study of Change

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Chemistry:

The Study of Change

Chapter 1

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


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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 Study of Chemistry

Macroscopic Microscopic


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The scientific methodis a systematicapproach to research

%2

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

tested modified


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# theoryis a unifying principle that e3plainsa (ody of facts and4or those laws that are(ased on them

%2

# lawis a concise statement of a relationship(etween phenomena that is always the same

under the same conditions

#tomic Theory

+orce 5 mass 3 acceleration


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% Matteris anything that occupies space andhas mass

$ # substanceis a form of matter that has adefinite composition and distinct properties

Chemistryis the study of matter and the

changes it undergoes

%6

Sugar7ater

Gold


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# mixtureis a com(ination of two or more su(stancesin which the su(stances retain their distinct identities

% Homogenous mixture8solution9 Thecomposition of the mi3ture is the samethroughout 8at the atomic4molecular le*el9

$ Heterogeneous mixture The composition is

not uniform throughout

#re these homogeneous.soft drin;, mil;, solder, salt water

#re these heterogeneous.cement, iron filings in sand

%6


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Physical meanscan (e used to separate a mi3tureinto its pure components

magnet

%6

distillation


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#n elementis a su(stance that cannot(eseparated into simpler su(stances (y chemicalmeans.

&%%6 elements ha*e (een identified

&


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#compoundis a su(stance composed of atomsof two or more elements chemically united in fi3ed

proportions

Compounds can only (e separated into theirpure components 8elements9 (y chemical

means

%6

7ater 8H$=9 Glucose 8C>H%$=>9

#mmonia 8H29


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Classifications of Matter


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The Three States of Matter

%?

solidli"uid

gas


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States of Matter


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7ater !roperties


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#physical changedoes not alter the composition oridentity of a su(stance

# chemical changealters the composition oridentity of the su(stance8s9 in*ol*ed

ice meltingsugar dissol*ing

in water

%>

hydrogen (urns inair to form water

!hysical or Chemical.


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+ormation of Sodium Chloride


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#n extensive property of a material depends upon

how much matter is is (eing considered

#n intensive property of a material does notdepend upon how much matter is is (eingconsidered

&mass

&length

&*olume

&density

&temperature

&color

)3tensi*e and Intensi*e !roperties

%>


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Matter - anything that occupies space and has mass

mass measure of the "uantity of matter

SI unit of mass is the kilogram8;g9

% ;g 5 %@@@ g 5 % 3 %@2g

weight force that gra*ity e3erts on an o(Aect

weight 5 c3 mass

on earth, c5 %@

on moon, cB @%

%

# % ;g (ar will weigh

% ;g on earth

@% ;g on moon


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%

International System of Dnits 8SI9


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%


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Volume SI deri*ed unit for *olume is cu(ic meter 8m29

% cm25 8% 3 %@-$m925 % 3 %@->m2

% dm25 8% 3 %@-%m925 % 3 %@-2m2

% E 5 %@@@ mE 5 %@@@ cm25 % dm2

% mE 5 % cm2

%


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Density SI deri*ed unit for density is ;g4m2

% g4cm25 % g4mE 5 %@@@ ;g4m2

density 5mass

*olume d5mV

%

# piece of platinum metal with a density of $%?g4cm2has a *olume of 66F cm2 7hat is its mass.

d5 mV

m5 d3 V5 $%? g4cm23 66F cm25 F>? g


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5 @C $2%?

@+ 5 3 @C 2$F?

%

$2 5 @ @C22 5 %@@ @C

2$ @+ 5 @ @C$%$ @+ 5 %@@ @C


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Con*ert %$F @+ to degrees Celsius

@

+ 5 3@

C 2$

F

?@+ 2$ 5 3 @CF

?

3 8@

+ 2$9 5@

CF

?

@C 5 3 8@+ 2$9F?

@

C 5 3 8%$F 2$9 5


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%@$,$@@,@@@,@@@,@@@,@@@,@@@,@@@

>@$$ 3 %@$2

The mass of a single car(on atom in grams:

@@@@@@@@@@@@@@@@@@@@@@@%FF

%FF 3 %@-$2

3 %@n

is a num(er(etween % and %@

nis a positi*e ornegati*e integer


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Scientific otation

%$

n > 0

?>$ 5 ?>$ 3 %@2

mo*e decimal left

@@@@@@$

n < 0

@@@@@@$ 5 $ 3 %@-6

mo*e decimal right

#ddition or Su(traction

% 7rite each "uantity withthe same e3ponent n

$ Com(ine %and $2 The e3ponent, n, remainsthe same

62% 3 %@4 2F 3 %@35

62% 3 %@4 @2F 3 %@45

6@ 3 %@4


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Scientific otation

% m 2significant figures

&Keros to the left of the first non1ero digit are notsignificant

@@< E %significant figure

&If a num(er is greater than %, then all 1eros to the right of thedecimal point are significant

$@ mg $significant figures&If a num(er is less than %, then only the 1eros that are at theend and in the middle of the num(er are significant

@@@6$@ g 2significant figures


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How many significant figures are ineach of the following measurements.

$6 mE $ significant figures

2@@% g 6 significant figures

@@2$@ m2 2 significant figures

>6 3 %@6molecules $ significant figures

?>@ ;g $ significant figures

%<


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Significant +igures

%>> 5 %>?2>2>> 5 %>?

2 sig figs round to2 sig figs

>< J %%$@6 5 @@>@>F$>

$ sig figs round to$ sig figs

5 @@>%

Si ifi +i


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Significant +igures

%>6, >>< and >@ 5 .

>>6 >>< >@

25 >>222 5 >>

ecause 2 is an exact number

5


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Accuracy how close a measurement is to the true*alue

Precision how close a set of measurements are to each other

accurateN

precise

precise(ut

notaccurate

notaccurateN

notprecise

%<


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%F

imensional #nalysis Method of Sol*ing !ro(lems

% etermine which unit con*ersion factor8s9 are needed

$ Carry units through calculation

2 If all units cancel e3cept for the desired units!, then thepro(lem was sol*ed correctly

gi*en "uantity 3 con*ersion factor 5 desired "uantity

gi*en unit 3 5 desired unitdesired unitgi*en unit


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%F

imensional #nalysis Method of Sol*ing !ro(lems

Con*ersion Dnit % E 5 %@@@ mE

%E

%@@@ mE%>2 E 3 5 %>2@ mE

%E%@@@ mE

%>2 E 3 5 @@@%>2@ E$

mE

How many mE are in %>2 E.


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The speed of sound in air is a(out 262 m4s 7hat isthis speed in miles per hour.

% mi 5 %>@F m % min 5 >@ s % hour 5 >@ min

262ms

3% mi

%>@F m

>@ s

% min3

>@ min

% hour3 5 >

mi

hour

meters to miles

seconds to hours

%F

conversion units


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Chemistry In #ction:


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Chemistry In #ction:

In %F6@ George Gamow hypothesi"edthat

the uni*erse (egan with a gigantic e3plosionor (ig (ang

)3perimental Support

&e3panding uni*erse

&cosmic (ac;ground radiation

&primordial helium

%2

!rimordial Helium and the ig ang Theory

Chemistry In #ction


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Chemistry In #ction

=n F4$24FF, O%$?,@@@,@@@ Mars Climate =r(iter entered MarPsatmosphere %@@ ;m 8>$ miles9 lower than planned and was

destroyed (y heat

% l( 5 %

% l( 5 66?

/This is going to (e thecautionary tale that will (eem(edded into introductionto the metric system inelementary school, highschool, and college sciencecourses till the end of time0

chapter 1 study of change

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