1. Chemistry - Fall Semester Final topics
Mr. Weissbard

2. Naming Chemical Compounds

3. Rule 1– If two identical elements combine then the name doesn’t change
These compounds are called “diatomic” meaning they have 2 atoms. Diatomic molecules are gasses at room temperature. H2 N2 O2 F2
Cl2
Br2 I2

4. Name these compounds Sodium + chlorine Magnesium + fluorine
Rule 2 – When two elements join and one is a halogen, oxygen or sulphur the name ends with ____ide
e.g. Magnesium + oxygen —> magnesium oxide
Sodium + chlorine
Magnesium + fluorine
Lithium + iodine
Chlorine + copper
Oxygen + iron
Name these compounds

5. Name these compounds
KBr
LiCl
CaO
MgS KF

6. e.g. Sodium + hydrogen + oxygen —> Sodium hydroxide
Rule 3 – When three or more elements combine and two of them are hydrogen and oxygen the name ends with hydroxide
e.g. Sodium + hydrogen + oxygen —> Sodium hydroxide
Potassium + hydrogen + oxygen
Lithium + hydrogen + oxygen
Calcium + hydrogen + oxygen
Mg(OH)2 may also be called Magnesium di-hydroxide

7. e.g. Copper + sulphur + oxygen Copper sulphate
Rule 4 – When three or more elements combine and one of them is oxygen the ending is _____ate
e.g. Copper + sulphur + oxygen Copper sulphate
Calcium + carbon + oxygen
Potassium + carbon + oxygen
Calcium + sulphur + oxygen
Magnesium + chlorine + oxygen
Calcium + oxygen + nitrogen

8. Name these compounds
AgNO3
H2SO4
K2CO3

9. Some common covalent and ionic compounds
Covalent formulae
H2O Water
CO2 Carbon Dioxide
NH3 Ammonia
H2 Hydrogen
O2 Oxygen
N2 Nitrogen
SO2 Sulfur Dioxide
Ionic formulae
NaCl Sodium Chloride
CaCl2
MgO
HCl
H2SO4
HNO3
NaOH
Ca(OH)2
CaCO3
Al2O3
Fe2O3

10. Avogadro’s Number
In 1865, Avogadro determined that a gasses properties were determined by the number of gas particles in a sample and not the specific properties of any particular gas molecule.
Later, in 1909, Perrin determined that there should be a unifying constant relating atomic mass and a measurable quality such as a sample’s weight in grams. Since this number would apply to Avogadro’s principle, Perrin named it Avogadro’s Number.
It was not until the 1950’s that accurate measurements of Avogadro’s number became possible. The measurements were based on x-ray diffraction of exactly 12 grams of Carbon12. Today, Tantalum is used as the standard.
Avogadro’s number is 6.02 x 10^23 particles (atoms or compounds) = 1 mole.

11. Using Avogadro’s Number
Find the weight of 1 mole of each of these chemicals
Hint: Total up the molecular weights of each component H2 He
12C
H2O
Al2O3

12. Find the number of moles
If you know the weight of a sample and its chemical composition, you can find the number of moles in a sample.
simply total up the elements in a compound, multiply each by their weight to get the molecular weight of the compound
next divide the weight of the sample by the molecular weight
example: 18 grams of H2O is 1 mole
example 36 grams of H2O is 2 moles
(notice the relation between MOLEcular weight and the unit MOLE)