Reference Guide
Ch 7: Compounds
Naming and Writing Formulas
These are your tabs on the bottom – label them.
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Metal to Non-metal Ionic Names_____
Metal to Non-metal Ionic Formulas___
Non-metal to Non-metal Molecular Names______
Non-metal to Non-metal Molecular Formulas____
Acids, Bases, and Salts
Monatomic:
1.
Positive Ions – use element name + ion. Ca2+ - Calcium ion
2.
Negative Ions – drop ending and add “ide”. Br1- Bromide ion
Binary:
1.
Write the cation first, followed by the anion.
2.
Metals that form more than one ion use Roman numerals to identify the
charge of the ion. Fe 3+ : Iron (III) ion Cu2+ : Copper (II) ion
3.
Add “ide” to the anion ending
Polyatomic Ions:
Use the chart Oxygen “ate” or “ite”
Multiple – use parenthesis
Metal to Non-metal Ionic Names
Examples:
Sodium Oxide Na2O
Ammonium Sulfate (NH4)2SO4
Calcium Nitrite Ca(NO2)2
Strontium Phosphate Sr3(PO4)2
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Binary Ionic Compounds:
1. Write the symbol of the cation first.
2. Charges of the ions are not included in
the chemical formula.
3. Determine the ratio of ions by doing the
“charge cross over”
1.
- the absolute value of each ions’ charge as
the subscript for the other ion.
Ionic Formulas
Examples:
N2O dinitrogen monoxide
SO2 sulfur dioxide
N2O3 dinitrogen trioxide
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1.
Element with lower group number is first. If in the
same group, greater period is first.
2.
Second element is an anion (ide)
3.
Greek prefixes determine number
1.
*no mono on first
Mono = 1
Di = 2
Tri = 3
Deca = 10
Tetra = 4
Penta = 5
Hexa = 6
Hepta = 7
Octa = 8
Nona = 9
Some compounds were discovered before the elements were
known so some covalent compounds have names that don’t
match their formulas. Ex. Water, ammonia, and methane.
Molecular Names
1.
The least electronegative element is written first.
2. Use prefixes to make the subscripts. If no prefix is present at
the beginning, one atom is used.
Molecular Formulas
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Acids – (begin with H and contain H+ ions) acids
increase the concentration of H+ in aqueous
solutions.
1.
a.
b.
Binary – 2 elements – usually hydrogen and a halogen.
Oxyacids – contain hydrogen, oxygen, and a third
element.
Bases – (contain OH- ion) – a substance that
increases the concentration of OH- ions in
aqueous solutions.
3. Salts – have a cation and an anion from an acid.
Ex. HCO3- (hydrogen carbonate ion and
Bicarbonate ion.)
Acids, Bases, and Salts
2.