chemistry - Wikispaces10+Section+3.pdf · Percent Composition and Chemical Formulas ... Percent Composition and Chemical Formulas 10.3 > Molecular Formulas ... chemistry Author: Andrea

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chemistry

© Copyright Pearson Prentice Hall

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Percent Composition and Chemical

Formulas

It helps to know the percents of

the components in a shirt

because they affect how warm it

is, whether it will need to be

ironed, and how it should be

cleaned. You will learn how the

percents of the elements in a

compound are important in

chemistry.

10.3


Percent Composition and

Chemical Formulas >

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The Percent Composition of a

Compound

The Percent Composition of a Compound

How do you calculate the percent by

mass of an element in a compound?

10.3

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Chemical Formulas > The Percent Composition of a

Compound

The percent by mass of an element in a

compound is the number of grams of the

element divided by the mass in grams of

the compound, multiplied by 100%.

10.3

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Compound

Percent Composition from Mass Data

The relative amounts of the elements in a

compound are expressed as the percent

composition or the percent by mass of each

element in the compound.

10.3


SAMPLE PROBLEM

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10.9


SAMPLE PROBLEM

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10.9


SAMPLE PROBLEM

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10.9


SAMPLE PROBLEM

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10.9


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Practice Problems for Sample Problem 10.9

ChemASAP/dswmedia/rsc/asap1_chem05_cmps1033.html

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Compound

Percent Composition from the Chemical Formula

10.3


SAMPLE PROBLEM

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10.10


SAMPLE PROBLEM

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10.10


SAMPLE PROBLEM

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10.10


SAMPLE PROBLEM

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10.10


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Problem Solving 10.34 Solve

Problem 34 with the help of an

interactive guided tutorial.


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Compound

Percent Composition as a Conversion Factor

You can use percent composition to calculate

the number of grams of any element in a specific

mass of a compound.

10.3

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Compound

Propane (C3H8) is 81.8% carbon and 18%

hydrogen. You can calculate the mass of carbon

and the mass of hydrogen in an 82.0 g sample of

C3H8.

10.3



Chemical Formulas >

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Empirical Formulas

Empirical Formulas

What does the empirical formula of a

compound show?

10.3

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Chemical Formulas > Empirical Formulas

The empirical formula gives the lowest whole-

number ratio of the atoms of the elements in a

compound.

The empirical formula of a compound

shows the smallest whole-number ratio

of the atoms in the compound.

10.3

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Chemical Formulas > Empirical Formulas

Ethyne (C2H2) is a gas used in

welder’s torches. Styrene

(C8H8) is used in making

polystyrene.

These two compounds of

carbon have the same

empirical formula (CH) but

different molecular formulas.

10.3


SAMPLE PROBLEM

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10.11


SAMPLE PROBLEM

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10.11


SAMPLE PROBLEM

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10.11


SAMPLE PROBLEM

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10.11


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Problem-Solving 10.37 Solve

Problem 37 with the help of an

interactive guided tutorial.




Chemical Formulas >

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Molecular Formulas

Molecular Formulas

How does the molecular formula of a

compound compare with the empirical

formula?

10.3


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Chemical Formulas > Molecular Formulas

The molecular formula of a compound is

either the same as its experimentally

determined empirical formula, or it is a

simple whole-number multiple of its

empirical formula.

10.3

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Chemical Formulas > Molecular Formulas 10.3

Methanal, ethanoic acid,

and glucose all have the

same empirical formula—

CH2O.

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Chemical Formulas > Molecular Formulas 10.3


SAMPLE PROBLEM

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10.12


SAMPLE PROBLEM

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10.12


SAMPLE PROBLEM

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10.12


SAMPLE PROBLEM

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10.12


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Section Quiz

-or- Continue to: Launch:

Assess students’ understanding

of the concepts in Section

10.3 Section Quiz.

10.3.



ChemASAP/dswmedia/rsc/ch10_sectn03_quiz.qtb


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1. Calculate the percent by mass of carbon in cadaverine,

C5H14N2, a compound present in rotting meat.

a. 67.4% C

b. 58.8% C

c. 51.7% C

d. 68.2% C

10.3 Section Quiz.


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2. Which of the following is NOT an empirical

formula?

a. NO2

b. H2N

c. CH

d. C3H6

10.3 Section Quiz.


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10.3 Section Quiz.

3. Determine the molecular formula of a

compound that contains 40.0 percent C, 6.71

percent H, and 53.29 percent O and has a

molar mass of 60.05 g.

a. C2H4O2

b. CH2O

c. C2H3O

d. C2H4O


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Chemical Formulas > Concept Map 10

Concept Map 10 Solve the

Concept Map with the help of

an interactive tutorial.

ChemASAP/dswmedia/rsc/asap1_chem05_cmcm1000.html

END OF SHOW

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chemistry - Wikispaces10+Section+3.pdf · Percent Composition and Chemical Formulas ... Percent Composition and Chemical Formulas 10.3 > Molecular Formulas ... chemistry Author: Andrea