Nomeclature

One name for each substance, one substance for each (valid)

name

If it is a…

• The nomenclature rules depend on what type of substance. There are several systems.

1. Ionic compounds

2. Covalent compounds

3. Acids

4. Organic chemicals (around Christmas)

5. Complex ions (around Spring Break)

Ionic compounds: Formula to name

• Name (don’t count) the ions.

• NaBr

• K2O

• (NH4)2CO3

• FeS

• CrI3

Ionic compounds: Formula to name

• Name (don’t count) the ions.

• NaBr sodium bromide

• K2O potassium oxide

• (NH4)2CO3 ammonium carbonate

• FeS iron (II) sulfide

• CrI3 chromium (III) iodide

Warnings

• Group metals (group 1 and 2 and aluminum) do not get a Roman numeral

• Count your charges to get the transition element charge. The Roman numeral is part of an ion’s name

• Watch out for Hg+2 vsHg2+2, O-2 vs O2

-2

Ionic compounds: Name to formula

• Balance your charges

• Lithium chloride

• calcium bromide

• Aluminum sulfate

• cobalt (II) oxide

• nickel (III) nitrite

Ionic compounds: Name to formula

• Balance your charges

• Lithium chloride LiCl

• calcium bromide CaBr2

• Aluminum sulfate Al2(SO4)3

• cobalt (II) oxide CoO

• nickel (III) nitrite Ni(NO2)3

Warnings

• Use () when you double or triple a polyatomic ion

• Balance your charges

Prefixes

1. Mono-

2. Di-

3. Tri-

4. Tetra-

5. Penta-

6. Hexa-

7. Hepta-

8. Octo-

9. Nona-

10. Deca-

11. Undeca-

12. Dodeca-

13. Trisdeca-

…

20. Icosa-

PS—Hydrated salts

• Hydrated salts are written with • x H20

• They are named with (prefix)hydrate

• For example:

Cobalt (II) chloride dihydrate = CoCl2• 2H20

Covalent compounds: Formula to name

• Name the atoms, in order, with prefixes (ends in –ide)

• N2S5

• CCl4• P2O5

• BF3

Covalent compounds: Formula to name

• Name the atoms, in order, with prefixes (ends in –ide)

• N2S5 dinitrogen pentasulfide

• CCl4 carbon tetrachloride

• P2O5 diphosphorus pentoxide

• BF3 boron trifluoride

Warnings

• First element is named, second one ends in “–ide”

• An “a” or “o” is dropped from the prefix before “–oxide”

• The “mono-” prefix is omitted on the first atom

Covalent compounds: Name to formula

• Write the atoms, prefixes become subscripts

• nitrogen trichloride

• Arsenic trioxide

• Bromine monochloride

• Xenon tetrafluoride

Covalent compounds: Name to formula

• Write the atoms, prefixes become subscripts

• nitrogen trichloride NCl3• Arsenic trioxide AsO3

• Bromine monochloride BrCl

• Xenon tetrafluoride XeF4

Acids

• If the anion name then the acid name

• ends in…. is…

Acids

• If the anion name then the acid name

• ends in…. is…

• --ide Hydro___ic acid

• (hypo--) --ite Hypo___ous acid

• --ite ___ous acid

• --ate ___ic acid

• (per--) –ate Per ___ic acid

AcidsFormula to name• HI is _________acid

• HBrO4 is _________acid

• H2CO3 is _________acid

• H2SO3 is ________acid

• HClO is ___________acid

AcidsFormula to name• HI is hydroiodic acid

• HBrO4 is perbromic acid

• H2CO3 is carbonic acid

• H2SO3 is sulfurous acid

• HClO is hypochlorous acid

Acids Name to formula

• ____is hydrocyanic acid

• ____ is periodic acid

• _____ is phosphoric acid

• _____ is nitrous acid

• ____ is hypoiodous acid

Acids Name to formula

• HCN is hydrocyanic acid

• HIO4 is periodic acid

• H3PO4 is phosphoric acid

• HNO2 is nitrous acid

• HIO is hypoiodous acid

Mass

1 amu x Avogadro’s number = 1 g

• The formula mass is the mass of a formula.

What is the formula mass?

• BaCO3

• Zn3(PO4)2

• NiCl2•6H2O

What is the formula mass?

• Iron (II) hydroxide

• Diphosphorus pentoxide

• Hypochlorous acid

MassMole

• 1 mole = Avogadro’s number of particles.

• Use the conversion:

1 mole = FM (in g)

How many moles?

• 12.8 g BaCO3

• 5.65 ng Iron (II) hydroxide

• 7.45 kg NiCl2•6H2O

What is the mass?

• .0153 mol Hypochlorous acid

• .15 mmol Zn3(PO4)2

• 5 mol NiCl2•6H2O

Some more mole conversions

1. A sample of HC2H3O2 has a mass of 20.0 g. How many atoms of carbon are present?

2. Calculate the mass of 1.50x1020 formula units of RbI.

3. Calculate the number of ions in 1.00 gram of Pb(C2H3O2)2

4. A sample of H3CCOCH3 has a mass of 20.0 g. How many moles of hydrogen are present?

5. Calculate the mass of 4.6 moles of I2(s).

One piece of general advice for the AP test:

“When in doubt: Convert to moles”

W H Bond

Mole conversions will include:

• Mass

• Particles (molecules, formula units, ions)

• Atoms (using subscripts in a formula)

• Volume of ideal gas at STP(1 mole=22.4L)

• Nonstandard conditions (n=PV/RT)

• Volume of a solution (n=Molarity x volume)

(Electrical current and time—consider later)

% composition

% = FM of all of that element x100%

(of an FM of the compound

element)

For example:

• FM MgSO4•7H20=246.48 g/mol• %Mg= 24.31 g/mol x 100% = 9.86%

246.48g/mol• %S = 32.06 g/mol x 100% = 13.01%

246.48g/mol• %O= 11 x 16.00 g/mol x 100% = 71.41%

246.48g/mol• %H= 14x1.008 g/mol x 100% = 5.73%

246.48g/mol

For example:

• FM MgSO4•7H20=246.48 g/mol• %Mg= 24.31 g/mol x 100% = 9.86%

246.48g/mol• %S = 32.06 g/mol x 100% = 13.01%

246.48g/mol• %O= 11 x 16.00 g/mol x 100% = 71.41%

246.48g/mol• %H= 14x1.008 g/mol x 100% = 5.73%

246.48g/mol

Did you catch that?

What is the % composition of…

• HBr

• Fe(OH)2

• NaCN

What is the % composition of…

• CH4

• C2H6

• C3H8

• C4H10

What is the % composition of…

• CH4= 25.14%H 74.86%C

• C2H6= 20.12%H 79.88%C

• C3H8= 18.29%H 81.71%C

• C4H10= 17.34%H 82.66%C

You will notice a similar effect with:

• HF

• HCl

• HBr

• HI

You will notice a similar effect with:

• HF = 5.04%H 94.96%F

• HCl = 2.76%H 97.23%Cl

• HBr = 1.24%H 98.76%Br

• HI = .79%H 99.21%I

You may also be given masses

• What is the % composition of a compound that is composed of 7.765 g H and 124.23 g O?

You may also be given masses

• What is the % composition of a compound that is composed of 7.765 g H and 124.23 g O?

• 5.88% H, 94.12% O

You may also be given masses

• What is the % composition of a compound that is composed of 7.765 g H and 124.23 g O?

• 5.88% H, 94.12% O

It’s NOT water! (11%H,88%O)

To find an empirical formula

Note: “empirical”–based on data, not theory.

To find an empirical formula

• Take the data (% or mass) and convert to moles.

• Divide by the smallest to find the simplest whole number ratio—the subscripts in the empirical formula.

For example:

• What is the empirical formula for a compound where a sample is found to contain 4.5156g H, 26.906g C and 11.946g oxygen?

For example:

• What is the empirical formula for a compound where a sample is found to contain 4.5156g H, 26.906g C and 11.946g oxygen?

Warning: This will give you an empirical formula only. An estimate of the molar mass will give you the molecular formula.

For example:

• What is the empirical formula for a compound where a 4.3368 g sample is burned to form 9.8596 g CO2 and 4.0362 g H20

For example:

• What is the empirical formula for a compound where a 4.3368 g sample is burned to form 9.8596 g CO2 and 4.0362 g H20

Will probably be given as the gas volume at some

conditions

For example:

• What is the empirical formula for a of a compound where a 3.309 g sample is burned to form 5.897 g CO2 and 2.414 g H20?

For example:

• What is the empirical formula for a of a compound where a 4.587 g sample is burned to form 11.451 g CO2 and 5.625 g H20?