Chemistry 100(02) Fall 2012 Instructor: Dr. Upali Siriwardane e-mail: [email protected] Office: CTH 311 Phone 257-4941 Office Hours: M,W, 8:00-9:00

Chemistry 100(02) Fall 2012 Instructor: Dr. Upali Siriwardane e-mail: [email protected]

Office: CTH 311 Phone 257-4941

Office Hours: M,W, 8:00-9:00 & 11:00-12:00 a.m Tu,Th,F 9:00 - 10:00 a.m.

Test Dates:

October 1, 2012 (Test 1): Chapter 1 & 2 October 22, 2012 (Test 2): Chapter 3 & 4 November 14, 2012 (Test 3) Chapter 5 & 6 November 15, 2012 (Make-up test) comprehensive: Chapters 1-6 9:30-10:45:15 AM, CTH 328

CHEM 100, Fall 2012 LA TECH 2-1

REQUIRED : Textbook: Principles of Chemistry: A Molecular Approach, 2nd Edition-Nivaldo J. Tro - Pearson Prentice Hall and also purchase the Mastering Chemistry Group Homework, Slides and Exam review guides and sample exam questions are available online: http://moodle.latech.edu/ and follow the course information links. OPTIONAL : Study Guide: Chemistry: A Molecular Approach, 2nd Edition-

Nivaldo J. Tro 2nd Edition Student Solutions Manual: Chemistry: A Molecular Approach, 2nd Edition-Nivaldo J. Tro 2nd

Text Book & Resources


Chapter 3. Molecules, Compounds, and Chemical Equations

3.1 Hydrogen, Oxygen, and Water 78 3.2 Chemical Bonds 80 3.3 Representing Compounds: Chemical Formulas and Molecular Models.. 82 3.4 An Atomic-Level View of Elements and Compounds 84 3.5 Ionic Compounds: Formulas and Names 87 3.6 Molecular Compounds: Formulas and Names 93 3.7 Formula Mass and the Mole Concept for Compounds 97 3.8 Composition of Compounds 100 3.9 Determining a Chemical Formula from Experimental Data 105 3.10 Writing and Balancing Chemical Equations 110 3.11 Organic Compounds 114


Chapter 3. KEY CONCEPTS ·Writing Molecular and Empirical

Formulas (3.3) ·Classifying Substances as

Atomic Elements, Molecular Elements, Molecular Compounds, or Ionic Compounds (3.4)

·Writing Formulas for Ionic Compounds (3.5)

·Naming Simple Ionic Compounds (3.5)

·Naming Ionic Compounds Containing Polyatomic Ions (3.5)

·Naming Molecular Compounds (3.6)

·Naming Molecular Compounds (3.6)

·Naming Acids (3.6) ·Calculating Formula Mass (3.7) ·Using Formula Mass to Count

Molecules by Weighing (3.7) ·Calculating Mass Percent

Composition (3.8)

·Using Mass Percent Composition

as a Conversion Factor (3.8) ·Using Chemical Formulas as Conversion Factors (3.8) ·Obtaining an Empirical Formula from Experimental Data (3.9) ·Calculating a Molecular Formula from an Empirical Formula and Molar Mass (3.9) ·Obtaining an Empirical Formula from Combustion Analysis (3.9) ·Balancing Chemical Equations (3.10)


Intramol ecular Chemical Bonding Types onic: Complete transfer of 1 or more electrons

from one atom to another, usually between a metal and a nonmetal element

Covalent: The sharing of val ence electrons shared between nonmetal elements

Metallic: The communal sharing of electrons between metals

*Note: Most molecular bonds are actually somewhere in between covalent and ionic types.


MOLECULAR Nonmetals only0

IONIC Metal and nonmetal

ACIDS* H and one or

more nonmetals

- • • • ■ 0 4 1 1 4 1 4 . ■ • . -

prefix name of

prefix 1st element

lbase name of

2nd element + -ide

Example: P20, diphosphorus pentoxide

Metal forms more than one type of ion

name of

cation (metal)

base name of anion (nonmetal)

+ -ide Example: Cali

calcium iodide

1- Oxyacids Contain oxygen

base name of oxyanion

+ -ic —,04/ Example: H1PO4

phosphoric acid

Binary acids Two-element

base name of anion (nonmetal) + -ide

hydro

0 1 ■ 0 . 4 „ .

acid name of cation (metal)

_■/".1

charge of cation (metal) in Roman numerals in parentheses

base name name of

nonmetal + -ic

s-

acid A.- 1

base name of oxyanion

[ + -ous Example: FeCI Example• 1-1C1(aq) Example: H2SW•aq) iron(in) chloride hydrochloric acid sulfurous acid

*Acids must be in aqueous solution.


Types of Compounds

ar or Covalent Compounds: B) Mo lecul

non-metal + non-metal nonmetal oxide or halides: SO2

Organic compounds: C3H8


MOLECULAR ACIDS*

Nonmetal H and one or 414_ only more nonmetals

Binary acids Two-element

Oxyacids Contain oxygen

base name of

oxyanion + -k

Example, II 3 PO4 phospliovi( acid

T base name of prefix 2nd element

+ -ide

name of 1st

element

prefix

(xiimplc:1);,05

diphosphorus pentoxide

CHEM 100, Fall 2012 LA TECH

Example'. HiS03(aq) sulfurous acid

*Acids mug be in aqueous

base Dame

of nonmetal

-ic

Example; HCI(ao) hydrochloric acid

2-8

CHEMICAL BONDS: THE FORCE BETWEEN ATOMS

What Makes a Molecule?

Structural formula

Space-filling model

H

H C H

H

Methane, CH4

2613 Pearson Educalwrt Inc


Molecular Compounds: Nonmetal

Name the most “metallic” of the nonmetals first.

+ Nonmetal

Change the ending of the nonmetal to “IDE.”

Indicate the number of atoms of the nonmetal by Latin prefixes. ·Mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca ·Examples:

– P2O5: diphosphorous pentaoxide – CO: carbon monoxide


For compounds composed of two non-metallic e ements, the more metallic element is listed first.

To designate the multiplicity of an el ement, Greek prefixes are used:

mono 1; di 2; tri 3; tetra 4; penta 5; hexa 6; hepta 7; octa 8

Naming Binary Molecu lar-Coval ent Compounds


1) H2O, Na3PO4, HCl, C2H6, NH3, KCl, CH4, NH4Cl, C6H12O6, Brass-

CuxZny, SO3, NaCl, CO2

Identify the types of compounds in the above list:

Molecular compound:

Ionic compound:

Alloy:

Organic:

Inorganic:


H2O, Na3PO4, HCl, C2H6, NH3, KCl, CH4, NH4Cl, C6H12O6, Brass-

CuxZny, SO3, NaCl, CO2

2) Which of the above compounds have Molecular formula:

Ionic formula:

Distinct empirical formula:


3) Indicating the type and number of atoms in a molecule of the covalent compound: C6H12O6.

a.C:

b.H:

c.O:

d.Molecular formula: e.Empirical formula:


Simple Binary M olecul ar Compounds

H2O water (common name)

NH3 ammonia (common name)

N2O dinitrogen oxide (nitrous oxide) NO nitrogen monoxide (nitric oxide) NO2 nitrogen dioxide

N2O4 dinitrogen tetroxide CO carbon monoxide CS2 carbon disulfide

SO3 sulfur trioxide

CCl4 carbon tetrachloride PCl5 phosphorus pentachlorid e

2-15

SF6 sulfur hexafluoride


4) Give systematic names to following binary inorganic molecular compounds

a) H2O: b) HCl: c) SF6:

d) BF3: e) N2O4: f) CCl4:

g) SO3: h) PCl3:


alkanes – CnH2n+2

E.g . C5H12 pentane

alkenes – CnH2n E.g. C2H4 ethene alkynes – CnH2n-2 E.g. C2H2 ethyne

alco hols – ROH E.g C2H5OH ethanol

Hyd rocarbons and Alco hols

where R refers to the hydrocarbon radical backbone created by substituting an -OH functional group for a H atom in the hydrocarbon

2-17 CHEM 100, Fall 2012 LA TECH

5) Give the common name of the following molecular compounds

a.NH3:

b.CH3COOH:

c.C6H12O6:

d.C2H5OH:


Acids

Types of acids ·Binary acids

·H+ and nonmetal anion

In aqueous solutions, acids contain the H+ cation and

·Oxyacids ·H+ cation and polyatomic anion

anion.

2-19 CHEM 100, Fall 2012 LA TECH

Naming Acid s

Formula starts with H

HCl Hyd rochl oric acid HNO3 Nitric acid

H2SO4 Sulfuric acid HClO3 Chloric acid

2-20

H3BO3 Boric acid

H3PO4 Phosphoric acid


Names of acid s and ions

HClO2 chlorous ClO2¯ chl

HClO3 chloric ClO3¯ chl

HClO4 perchloric ClO4¯ perchl

HNO3 nitric NO3 ¯ nitrate


HClO hypochlorous

HNO2 nitrous NO2 ¯ nitrite

ClO ¯ ”hypochlorite

orate

orite

orate

2-21

formula ends with OH

Naming bases

NaOH

Ba(OH)2 barium hydroxid KOH

sodium hydroxid

potassium hydroxid

e

e

e

2-22

Ca(OH)2 calcium hyd

NH4OH roxide

ammonium hydroxid e


6) Give the names of the following acids Formula Name Ion (s) Formula Name Ions(s)

a) HNO3:

b) H3PO4:

c) HNO2:

d) H3PO3:

e) H2SO4:

f) H2CO3:

g) H2SO3:

h) CH3COOH:


Types of Chemical Formula

Molecular Shows ratio of atoms each element in the

: C2H6O Condensed

Shows groups of atoms bonded together in the formula. E.g ethyl alcohol: CH 3CH2OH

Structural Shows bonding of important groups in the formu

E.g ethyl a cohol :

a

2-24

compound. E.g ethyl alcohol


2-25

Models of Ethanol


7) Given the structural formula of an organic compound, write the for the following: CH3CHClCH2OH

a.molecular formula

b.condensed formula

c.structural formula

d.line formula


2-27

Catenation The formation of chains of atoms of the same

This key feature of carbon permits a vast number of compounds to exist.

Four types of hydrocarbons 1.Alkanes (saturated): single C-C bonds 2.Alkenes (unsaturated): double C=C

bond 3.Alkynes (unsaturated): triple bond 4.Aromatic (unsaturated): benzene rings

Hyd

e ement.

rocarbons


Alkanes CnH2n+2

methane – CH4

ethane – C2H6

propane – C3H8

butane – C4H10

pentane – C5H12

hexane – C6H14

heptane – C7H16

octane – C8H18

nonane – C9H20

decane – C10H22


Base names of hydrocarbons Prefix Carbons

Meth- 1 Eth- 2 Prop- 3 But- 4 Pent- 5 Hex- 6 Hept- 7 Oct- 8

- 9 Dec- 10

2-29

I see much memorization in

your future!

Non


8) Name, molecular, condensed and line formula of straight chain alkane (saturated hydrocarbons) or n-alkanes.

a.4 carbon n-alkane:

b.7 carbon n-alkane:


What is an Isomer? Compounds with the same number and type

of atoms but with different arrangements are called constitutional isomers

Condensed formul

Mol ecul ar Formula C5H12

as.

CH3CH2CH2CH2CH3 pentane

CH3CH(CH3)CH2CH3 2-methylbutane

(CH3)4C 2,2-dimethylpropane

All are isomers of C5H12. CHEM 100, Fall 2012 LA TECH 2-31

Alkane Isomers is there a formula?

Molecular Number of Molecular Number of Formula Isomers Formula Isomers

CH4 1

C2H6

C3H8 1

C4Hio 2

C51-112 3

C61-114 5

C71-116 9

C81-11 18

C9H20

C10112

2

Cl2H26 C

151132

C 201142

C 30H62

C40H82

35

75

355

4,347

366,319

4,111,846,763

62,491,178,805,831


9) Draw the structural formula of constitutional isomers of butane with molecular formula C4H10.

a.n-butane: CH3CH2CH2CH3

b.isobutene: (CH3) 3CH


2-34

Butane

Butane molecules are present in the liquid and gaseous states in the lighter


Determine empirical formulas for the following:

1. An ionic compound that has two aluminum ions for every three oxide ions

2.Hexane, C6H14

3.Arabinose, C5H10O5

4.Hydrogen peroxide,

Al2O3

(C3H7)n where n = 2

(CH2O)n where n = 2

(HO)n where n = 2


Classifying Organic Compound s

Examples Functional Group Ending

Hydrocarbons C and H only -ane Alcohols R-OH -ol

Acids R-COOH Amines R-NH2 -amine Ketones R(C=O)R’ -one Aldehydes R-CHO -al

-oic acid


10) Classification and the name of the following

g p

Classification Name

a.CnH2n+2 where n is 8:

a.CH3CH2CH2CH2-OH:

a.CH3CH2CH2-COOH:

a.CH3CH2CH2CH2CH2CH2-NH2:

a.CH3CH2-(C=O)-CH3:

d) CH3CH2-CHO:


2-37

The Many Representations of a Molecule TABLE 3.1 Benzene, Acetylene, Glucose, and Ammonia

Name of Empirical Molecular Structural Compound Formula Formula Formula Ball-and-Stick Model Space-Filling Model

Benzene CH C6H6

H

'C' C ,H

II

H

Acetylene CH C 2 H 2 4-1199 -4

Glucose CH2O C6H1206

0

CH H

—C —OH

HO—C—H

H— C —OH

H—C —OH

OH

Ammonia

CHEM 100, F—.. _

NH3 NH3

H a

11) Identify the classification or name of the following biologically important molecules

a) b) c)

d) e) f)


Documents

Chemistry 100(02) Fall 2012 Instructor: Dr. Upali Siriwardane e-mail: [email protected] Office: CTH 311 Phone 257-4941 Office Hours: M,W, 8:00-9:00