general chemistry lectures- chapter 1 (autosaved)

8/14/2019 General Chemistry Lectures- Chapter 1 (Autosaved)

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General Chemistry Lectures:

Chapter 1: Chemistry: The Study of Change

Chemistry- It is the study of matter and the changes it undergoes

Some Applications of Chemistry:

1.) Health and Medicine2.) Energy and the Environment3.) Materials and Technology4.) Food and Agriculture

Scientific Method- It is the systematic approach to research.

Data obtained from the research can be:

1.) Qualitative- It consists of general observation about the system.2.) Quantitative- It comprises numbers obtained by various measurements of the system.

Hypothesis- It is a tentative explanation for a set of observations.

Law- It is a concise verbal or mathematical statement of a relationship between phenomena that is

always the same under the same condition.

Theory- It is a unifying principle that explains a body of facts and/ or those laws that are base on them.

Classifications of Matter:

Matter- It is anything that occupies space and it has mass.

Substance-It is a form of matter that has a definite composition and distinct properties.

Mixture- It is a combination of two or more substances in which the substances retain their distinct

identities.

Homogeneous mixture- It is a mixture in which the composition is uniform all throughout.

Heterogeneous mixture- It is a mixture in which the composition is not uniform.

Elements- They are substances that cannot be separated into simpler substances by chemical means.

Compounds- They are substances that composed of two or more elements and united in fixed

proportions.

States of Matter:

1.) Solid


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2.) Liquid3.) Gas4.) Plasma5.) Bose-Einstein Condensate

Physical Properties- They are properties that can be measured and observed without changing its

composition or identity of the substance.

Chemical Properties- They are properties that can be measured and observed when the substance

undergoes chemical reaction.

Extensive Properties- They are properties that depends on the amount of matter.

Intensive Properties- They are properties that is independent on the amount of matter.

Mass- It is the measure of the amount of matter.

Weight- It is a force that gravity exerts on the object.

Density- It is the mass per unit volume of a substance.

Equation:

Temperature:

Formulas:


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Where:

Scientific Notation- It is used in handling very small or very large numbers.

It is in the form where N is a number between 1 to 10 and n is an exponent which is an integer.Addition and Subtraction

- In adding or subtracting numbers involving scientific notation, we first write each quantity- say with the same exponent n. Then, we combine and exponents remainthe same.

Multiplication and Division

- In multiplying numbers involving scientific notation, we multiply but add theirexponents. In dividing numbers involving scientific notation, we divide and subtracttheir exponents.

Significant Figures

- They are meaningful digits in a measured or calculated quantity.Guidelines for Significant Figures:

1.) Any digit that is not zero is significant.2.) Zeros between nonzero digits are significant.3.) Zeros to the left of the first nonzero digit are not significant.4.) If the number is greater than 1, then all the zeros written to the right of the decimal point count

as significant figures. If the number is less than 1, then only the zeros that are the end of the

number and the zeros between two nonzero digits are significant.

5.) For numbers do not contain decimal points, the trailing zeros ( that is, zeros after the lastnonzero digit.) may or may not significant.

Accuracy

- It tells us how close a measurement is to the true value of the quantity being measured.


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Precision

- It refers on how closely two or more measurements of the same quantity agree with oneanother.

Factor Label Method

- It is used to convert one unit to another using the relationship between two different units.Problems:


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1.21.) Given:

Required: =?

Solution:

1.22.) Given:

Required: m=?

Solution:

1.23.) Given

a.) b.) c.) .) d.) Required:

Convert a.) to d.) to Solution:


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a.)

b.)

c.)

d.) 1.24.) Given

a.) b.) c.) .) Required:Convert a.) to And b.) and c.) to =?Solution:

a.)

b.)

2


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c.) 2 1.25.) Given:

a.) b.) c.) Required:

Convert a.) to c.) to Solution:

a.) b.)

c.) 1.26.) Given:

a.)

b.) c.) Required:

Convert a.) to c.) to


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1.29.) Given

a.) 0.000000027

b.) 356


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c.) 47,764

d.) 0.096

Required:

Convert a.) to d.) in scientific notation: 1.30.) Given:

Required: Convert a.) and b.) to decimals.

1.31.) Given:

Required:

Express the answers from a.) to d.) in scientific notation:

Solution:


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1.32.) Given:

Required:

Express the answers from a.) to d.) in scientific notation:

Solution:


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1.33.) Given:

Required: Find the number of significant figures from a.) to h.)=?

Answer:


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a.) 4

b.) 2

c.) 5

d.) 2

e.) 3

f.) 1

g.) 1

h.) 2

1.34.) Given:

a.) 0.006 L

b.) 0.0605 dm

c.) 60.5 mg

f.) 6 kg

g.) 60 m

Required: Find the number of significant figures from a.) to g.)=?

Answer:

a.) 1

b.) 3

c.) 3

d.) 4

e.) 3

f.) 1

g.) 1


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1.35.) Given:

a.) 5.6792 m + 0.6 m +4.33 m

b.) 3.70 g 2.9133 g

c.) 4.51 cm x 3.6666 cm

Required: Express the answers with the correct number of significant figures:

Solution:

a.)

1.36) Given: Required: Express the answers with the correct number of significant figures from a.) to c.)=?

Solution:


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c.)

1.37.) Given:

a.) 22.6 m

b.) 25.4 mg


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Required:

a.) Convert 22.6 m to dm=?

b.) Convert 25.4 mg to kg=?

Solution:

( ) ( ) ( )

1.38.) Given:

a.) 242 lb

Required:

a.) Convert 242 lb to mg=?

Solution:

( ) ( ) ( )

1.39.) Given:

Mass of Gold= 1.00 g

Required: Cost of Gold =?


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Solution:

( )

1.40) Given:

1 solar year= 365.24 days

Required: Convert 365.24 days to seconds=?

Solution:

(

) (

) (

) 1.41.) Given:

Distance= 93 million miles

Required: Time in min. =?

Solution:

( ) 1.42.) Given:

Distance= 1 mile

Time= 13 min

Required:

Speed in


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a.) in./s =?

b.) m/min=?

c.) km/h=?

Solution:

( ) ( ) ( ) ( )

( )

(

) (

)

1.43) Given:

Height= 6.0 ft

Weight= 168 lb

Required:

Express height in meters and weight in kilograms.

Solution:


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( )

( )


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1.44) Given

Speed= 55 miles/hour

Required:

Convert 55 miles/hour to km/hr=?

Solution:

( )

1.45.)Given:

Speed= 62 m/s

Required:

Convert 62 m/s to miles/ hour=?

Solution:

( ) ( ) 1.46.)

Given:

Required:

Mass of Lead=?

Solution:


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( )

1.47.) Given:

a.)Distance= 1.42 lightyears

b.) 32.4 yds.

Required:

a.)Convert a.) to miles=?

b.) Convert b.) to cm=?

c.) Convert c.) to ft/s=?

Solution:

( ) ( ) ( ) ( )

1.48.) Given:

a.) b.)


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Required:

a.) Convert a.) to

=?

b.) Convert b.) to =?c.) Convert c.) to =?d.) Convert d.) to L=?

Solution:

( ) ( ) 1.49) Given:

Required:

Solution:


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( ) ( )

1.50)

Given:

Required:

Solution:

( )


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1.53.) Given:

Required:

Solution: ( ) 1.54.) Given:

Required:

Solution:

But for rectangular bar,

Working Equation:

1.55) Given:


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c.) Required:

Find the mass for a.) to c.)=?

Solution: But

Working Equation:

But:

Working Equation:

[ ( )]


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Given:

Required:

Solution:

But:

1.58.)Given:

Required:

Solution:

( ) ( )


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1.59)

Given:

Required:

Solution:

But:

(

)

1.61) Given:

Required:

Solution:


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1.62.) Given: Required:

Solution:

1.63.)

Given:

In Error= In Error= True Value= Required:

Percent Error in Solution:

||


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Convert

| | In | |

1.64.) Given;

Required:

Solution:

( ) ( ) 1.65.)

Required:

Find the temperature in which Celsius Reading is equal to Fahrenheit Reading=?

Solution:


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