chemical bonding: names and formulas

54
1 Chemical Names & Formulas Water Ammonia Methane

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Page 1: Chemical Bonding: Names and Formulas

1

Chemical

Names & Formulas

Water Ammonia Methane

Page 2: Chemical Bonding: Names and Formulas

2

Why “Systematic Names” ?

# atomic particles 3 (p, n, e)

# elements 110+

# elements in

earth’s crust (99%)

8

# elements in all

living things

25

# compounds >14,000,000

Page 3: Chemical Bonding: Names and Formulas

3

Why “Systematic Names” ?

Water H2O

Lime CaO

Lye NaOH

Potash K2CO3

Table Salt NaCl

Laughing Gas N2O

Baking Soda NaHCO3

Page 4: Chemical Bonding: Names and Formulas

4

Atoms and Ions

Atom:

neutral

no net charge

(# p+ = # e-)

e.g. Na 11 p+ and 11 e-

Cl 17 p + and 17 e-

Page 5: Chemical Bonding: Names and Formulas

5

Ion:

atom (or group of atoms)

has + or – charge

has more or less e-

only the # of e-

changes

e.g. Na+ 11 p+ and 10 e

-

Cl- 17 p + and 18 e-

Atoms and Ionse-

e-e-

e-

e-

Page 6: Chemical Bonding: Names and Formulas

6

Atoms and Ions

Na vs. Na+

and

Cl vs. Cl-

Very

different

Demo: Fe vs. Fe+3

Page 7: Chemical Bonding: Names and Formulas

7

Ions

Positive charge: “cation”

Na+ Ca2+ Al3+

Negative charge: “anion”

Cl- O2- SO42-

These atoms lost electrons

These atoms gained electrons

Page 8: Chemical Bonding: Names and Formulas

8

Compounds

Substances composed of 2

or more different atoms

HCl NaCl CO2

Page 9: Chemical Bonding: Names and Formulas

9

Chemical Formulas

Shows the kinds and

numbers of each type of atom

in a chemical compound.

Water = H2O

two atoms of H one atom of O

Page 10: Chemical Bonding: Names and Formulas

10

Compounds

•Atoms

bonded

as a unit

•Ions held

together by +

and - charges•nonmetals •metal + nonmetal

Molecular Ionic

e.g. H2O e.g. NaCl

Charges NOT shown

Page 11: Chemical Bonding: Names and Formulas

11

Molecular &

Ionic Compounds

Page 12: Chemical Bonding: Names and Formulas

12

1. Molecular FormulasMolecules are represented by

molecular formulas: discrete

units of bonded nonmetals.

e.g H2O & CO2

“covalent”

bondO

H H

“structural” formula for water

Page 13: Chemical Bonding: Names and Formulas

13

Naming Molecular

Compounds

(bonded nonmetal atoms)

prefix-1statom-prefix-2ndatom-ide

number

N2O5 = dinitrogen pentoxide

Page 14: Chemical Bonding: Names and Formulas

14

Number Prefix

1 Mono

2 Di

3 Tri

4 Tetra

5 Penta

6 Hexa

7 Hepta

8 Octa

9 Nona

10 Deca

Note: don’t

use ‘mono’ for

the first atom.

Page 15: Chemical Bonding: Names and Formulas

15

Try It

CO2 N2O

PCl3 SF6

SO3N2O4

H2ODangerous

chemical

Page 16: Chemical Bonding: Names and Formulas

16

Ionic Formulas

NaCl

“ionic” bond

Na+ and Cl-

Ionic compound is represented

by a formula unit, the lowest

ratio of atoms in the compound.

Page 17: Chemical Bonding: Names and Formulas

17

Naming Ionic Compounds

(positive metal ion +

negative nonmetal ion)

First must

learn ion

names and

charges!

Page 18: Chemical Bonding: Names and Formulas

18

Monatomic Ions

(single atom ions)

Charge from Periodic Table

Metals form cations (+)

Mg loses two e- to form Mg+2

Nonmetals form anions (-)

The name ends in “ide”

Cl gains one e- to form Cl-

Page 19: Chemical Bonding: Names and Formulas

19

1 2 13 14 15 16 17 18

Li+ Be2+ N3- O2- F-

Na+ Mg2+ Al3+ P3- S 2- Cl-

K+ Ca2+ As3- Se2- Br-

Rb+ Ba2+ I-

Common Monatomic Ions

end in --ide

+1 +2 +3 -3 -2 -1

Page 20: Chemical Bonding: Names and Formulas

20

Monatomic Ions: Try It!!!When the following elements

become ions, state:

ion name

charge

number of e- lost or gained

Ca

S

K

Br

P

Al

Page 21: Chemical Bonding: Names and Formulas

21

Monatomic Ions:

Some metals can form

two different types of ions.

Iron: Fe+2 and Fe+3

Copper: Cu+1 and Cu+2

•See Periodic Table for charges.

Page 22: Chemical Bonding: Names and Formulas

22

•Stock System:

“atom (charge)”

Multiple Charges: Names

Fe2+ is Iron(II) ion

Fe3+ is Iron(III) ion

Page 23: Chemical Bonding: Names and Formulas

23

•Classical System:

Latin name ending in

“ous” for lower charge

“ic” for the higher charge

Fe2+ is Ferrous ion

Fe3+ is Ferric ion

Multiple Charges: Names

Page 24: Chemical Bonding: Names and Formulas

24

Ion Stock Classic

Cu+ Copper(I) Cuprous

Cu2+ Copper(II) Cupric

Pb2+ Lead(II) Plumbous

Pb4+ Lead(IV) Plumbic

Sn2+ Tin(II) Stannous

Sn4+ Tin(IV) Stannic

Others

Page 25: Chemical Bonding: Names and Formulas

25

Polyatomic Ions

Some atoms group together

as a unit to form an ion.

-

NO3-

Page 26: Chemical Bonding: Names and Formulas

26

nitrate ion

NO3- PO4

3-

phosphate ion

sulfate ion ammonium ion

SO42-

NH4+

Polyatomic Ion: Charged

group of atoms acting as a unit

Page 27: Chemical Bonding: Names and Formulas

27

Regents Table ‘E’Note “ite” & “ate” pairs

--ite --ate

sulfite: SO32- sulfate: SO4

2-

nitrite: NO2-

nitrate: NO3-

chlorite: ClO2- chlorate: ClO3

-

Be able to recognize them !!!

Page 28: Chemical Bonding: Names and Formulas

28

Ionic Formulas

Name: cation then anion name

•Potassium chloride

K+ Cl-

KCl

Charges must “balance”

But don’t write charges!

Page 29: Chemical Bonding: Names and Formulas

29

Ionic Formulas•Calcium bromide

Ca2+ Br-

CaBr2(balance charge)

•Copper(I) sulfate

Cu+ SO42-

Cu2SO4

Page 30: Chemical Bonding: Names and Formulas

30

Shortcut “Criss Cross”

Cu+ SO42-

Cu2(SO4)1 = Cu2SO4

Copper(I) sulfate

Need to recognize polyatomic ions

Page 31: Chemical Bonding: Names and Formulas

31

Shortcut “Criss Cross”

Ca2+ S2-

Ca2S2 = CaS (reduce)

Calcium sulfide

Page 32: Chemical Bonding: Names and Formulas

32

Shortcut “Criss Cross”

Fe3+ CO32-

Fe2(CO3)3

Iron(III) Carbonate

(brackets needed

for polyatomic ion

with subscript)

Page 33: Chemical Bonding: Names and Formulas

33

Name or Give the Formula

of That Compound!!!

Silver chloride

CuBr2

Ammonium bromide

Mg3(PO4)2

Calcium chromate

Page 34: Chemical Bonding: Names and Formulas

34

Try Some More!!

N2O5

PCl3

AlCl3

Sodium hydrogen sulfate

SnO2

Page 35: Chemical Bonding: Names and Formulas

35

General PropertiesMolecular Compounds

Weak “intermolecular forces”

(molecular attractions)

Low melting & boiling points

Ionic Compounds

Strong ionic attractions

High melting & boiling points

Page 36: Chemical Bonding: Names and Formulas

36

Naming Acids•Acids are a special class of

compounds with H+ as the cation.

Example:

H+ with Cl-

HCl(aq)

where (aq) = dissolved in water

Page 37: Chemical Bonding: Names and Formulas

37

Naming AcidsAcids are named

according to the anion.

1. If the anion ends in –ide,

the acid is hydro----ic acid.

Cl-

is chloride

HCl(aq) is hydrochloric acid

Page 38: Chemical Bonding: Names and Formulas

38

Naming Acids

2. If the anion ends in –ite,

the acid is ----ous acid.

SO32- is sulfite

H2SO3(aq) is sulfurous acid

Page 39: Chemical Bonding: Names and Formulas

39

3. If the anion ends in –ate,

the acid is –ic acid.

Naming Acids

NO3- is nitrate

HNO3(aq) is nitric acid

Page 40: Chemical Bonding: Names and Formulas

40

Naming Acids: Try It

Name

HCN(aq)

HClO4(aq)

HClO(aq)

HCl(aq)

Page 41: Chemical Bonding: Names and Formulas

41

Naming Acids: Try It

Write the formula for:

carbonic acid

nitrous acid

Regents Table K

Page 42: Chemical Bonding: Names and Formulas

42

Summary:

Names & Formulas•Atoms vs. ions

Na Na+

•Compounds:

-molecular (nonmetals)

-ionic (metal + nonmetal)

cation(+) anion(-)

Page 43: Chemical Bonding: Names and Formulas

43

Summary:

Names & Formulas

•Molecular compound:

-prefix-atom-prefix-atom-ide

N2O5 = dinitrogen pentoxide

Page 44: Chemical Bonding: Names and Formulas

44

Summary:

Ionic compounds

-know names & charges

•monatomic ions (PeriodicTable)

•transition metals

-stock system: iron(II)

•polyatomic ions: NO3-

•compound name: cation+anion

Page 45: Chemical Bonding: Names and Formulas

45

Page 46: Chemical Bonding: Names and Formulas

Warm-up

46

How many p+ and e- in Ca and Ca+2?

Is Ca+2 and anion or cation?

What are the two general types of

compounds?

How do you recognize each?

Page 47: Chemical Bonding: Names and Formulas

Warm-up

47

Name NO2 and N2F4

Page 48: Chemical Bonding: Names and Formulas

Warm-up

48

Give the symbol and the name of the ion

that each element forms:

Mg Al P Br

How do you know NH4NO3 is ionic even

though it has only nonmetal atoms?

Page 49: Chemical Bonding: Names and Formulas

Warm-up

49

2. Name N2O and Al2(SO4)3.

Molecular Ionic

Types of atoms

Name of formula

Name of bond

1. Fill in the table:

Page 50: Chemical Bonding: Names and Formulas

Name or give formula:

50

gold(I) sulfate S2Cl5

barium phosphide Fe3(PO4)2

calcium hydrogen carbonate

Page 51: Chemical Bonding: Names and Formulas

Warm-up

51

Write the formula unit for

sodium sulfate.

Why can’t this formula be

reduced?

Page 52: Chemical Bonding: Names and Formulas

Name or give formula:

52

NH4+ magnesium nitride

S-2 calcium sulfate

SO3-2 aluminum hydrogen sulfate

NaCN barium phosphate

SnO FeC2O4

PBr3 N2O

SO3 Au2SO4

OH-

Page 53: Chemical Bonding: Names and Formulas

Warm-up

53

Name or write formula:

•H2SO3

•Hydroiodic acid

•N2S4

•FeSO3

Page 54: Chemical Bonding: Names and Formulas

Warm-up

54

Name or write formula:

•lead(IV) carbonate

•barium nitride

•CO

•SnS2•sulfurous acid