Unit b matter and chemical change notes(compounds & properties)

1. Compounds

2. Compounds
Compound: A chemical combination of two or more elements
in a specific ratio
Examples (Write One):
• Table Salt : NaCl (sodium chloride)
• Baking Soda : NaHCO3 (sodium bicarbonate)
• Water : H2O (dihydrogen oxide)

3. Compounds
Chemical Formula: Identifies the elements in the compound
and the number of each element.
Examples (Write One):
• Table Salt : NaCl (sodium chloride)
• Baking Soda : NaHCO3 (sodium bicarbonate)
• Water : H2O (dihydrogen oxide)

4. Compounds
Nomenclature: Naming system created by French chemist
Guyton de Morveau in 1787.
If you know the formula you can determine the name. If you
know the name you can determine the formula.

5. NaCl Salt
(sodium ​chloride)
1 atom Na
1 atom Cl
H2O Water
(dihydrogen ​oxide
)
2 atoms H
1 atom O
C6H12O6 Glucose 6 atoms C
12 atoms H
6 atoms O
H2SO4 Battery Acid
​(sulfuric acid)
2 atoms H
1 atom S
4 atoms O
CH3COOH Vinegar
(acetic ​acid)
2 atoms C
4 atoms H
2 atoms O

6. Compounds
The Subscript (the small number behind some elements) tells you how
many of the element are in that compound.
After a chemical formula we can also have subscript letters in parentheses.
This lets us know the state of the compound.
(s) is a solid
(l) is a liquid
(g) is a gas
(aq) is an aqueous solution (a substance dissolved in water)

8. Compounds
There are two different types of compounds depending on the types of
elements that make the compound.
They Are:
Ionic
Compounds
Molecular
Compounds

9. Ionic Compounds
Ionic Compounds: Contain at least one metal and one or more non-metal
Examples:
NaCl : Sodium chloride CuSO4 : Copper (II) Sulphate

10. Ionic Compounds
When a metal and non-metal combine they form IONIC bonds
In order to form a compound the metal loses electrons and becomes
positively charged.
The non-metal gains electrons and becomes negatively charged.
These charged elements are known as Ions.

11. Ionic Compounds

12. Ionic Compounds
Magnesium chloride is an ionic compound.
Its chemical formula is MgCl2
That is 1 Mg and 2 Cl
Mg
-
-
-
-
- -
-
-
--
- -
The two outer electrons ​of the
metal are given to the chlorine
atoms, ​filling their
outer ​electron shell

13. Ionic Compounds
Properties of Ionic Compounds:
• High melting point
• Good conductivity
• Distinct crystal shape
• Solid at room temperature
Polyatomic ions - some atoms bond together and have an overall positive or
negative charge. these groups of atoms act as one.

14. Molecular Compounds
Molecular Compounds: Molecular compounds contain only non-metals
Examples:
N2O4: Dinitrogen tetraoxide P4O10: tetraphosphorus decaoxide

15. Molecular Compounds
Molecular compounds form
COVALENT bonds
In order to form a compound
the non-metals must share
electrons in order to fill the
outer shell of each element.

16. Molecular Compounds
N
-
-
-
-
-
- -
Nitrogen trichloride is a
molecular ​compound. Its chemical
formula is NCl3
Each chlorine ​shares one electron
with the nitrogen. ​The
nitrogen ​shares 3 ​electrons, one
for ​each chlorine.

17. Molecular Compounds
Molecular Compounds:
• Solid, liquid or gas at room temperature
• Lower melting and boiling points because the covalent bond is weaker
than ionic bond

18. Practice
Identify the following chemicals as either ionic ​compounds or molecular
compounds
Sodium
Chloride
Ionic Magnesium
​chloride
Ionic
H20 Molecular Tin(IV) oxide Ionic
SO2 Molecular Dinitrogen
pentaphosphide
Molecular
Nickel (II)
bromide
Ionic SiO2 Molecular
Carbon
monoxide
Molecular Mn2O7 Ionic