Upload
others
View
8
Download
0
Embed Size (px)
Citation preview
Name: _____________________________ Date: ___________________ Period: _______
Practice 6.2: Writing Ionic Formulas Part II When writing chemical formulas for ionic compounds keep in mind these rules:
x The metal ion is always written first in the formula. x The metal ion and the non-metal ion charges MUST always add up to zero. x Never write the number “1” as a subscript: EXAMPLE: H2O not H2O1
The steps: 1. Write the charges of each ion. Ex: Ca+2 N-3 2. If they automatically add up to zero, smash them together. Ex: Ba+2 O-2 o BaO 3. If they don’t add up to zero, do a criss-cross on them. (Leave out the “+” and “-” signs). Ex:
Ca+2 N-3
Ca 3 N 2 4. Polyatomic ions are group of ions that act as 1 BIG ion. If you need more than one of these in
the formula, use parenthesis and write the subscript outside. Ex:
Ba+2 CN-1
Ba (CN) 2 Part A: Name/Write the following ions
Name Ion Nitride
O2-
Fluoride
Cl-
Bromine
I-
Sulfide
Fe2+
Lithium
Na+
Magnesium
Ca2+
Name: _____________________________ Date: ___________________ Period: _______ Part B: Write the formulas for the following compounds Ions Formula Calcium with chloride Ca2+ Cl- CaCl2
Barium with oxygen
Lithium with nitrogen
Aluminum with fluorine
Calcium with oxygen
Cesium with nitrogen
Aluminum with oxygen
Potassium with sulfur
Magnesium with bromine
Sodium with iodide
Part C: Write the formulas for the following polyatomic compounds Ions Formula Aluminum with hydroxide Al3+ OH- Al(OH)3
Sodium with carbonate
Calcium with phosphate
Barium with acetate
Potassium with chromate
Rubidium with cyanide
Magnesium sulfate
Aluminum phosphate
Sodium bicarbonate
Unit 6.3
1. Do criss-cross to get formula.
2. Draw each outer orbital diagram for each atom.
3. Use an arrow to show the transfer from the metal to the nonmetal.
� Ex. �Mg +2 Cl -1 so....MgCl2� Mg ÇÈ� Cl ÇÈ ÇÈ ÇÈ Ç� Cl ÇÈ ÇÈ ÇÈ Ç
� Use an orbital diagram to show the transfer of e-- between potassium and oxygen.
� K +1 O -2 so....K2O
� Use an orbital diagram to show the transfer of e-- between aluminum and sulfur� Al2S3
� Cation is named first� Group 1 and 2 and Al are “as is”� transition elements – element name followed by (roman numeral) for
the charge� Ex. Fe2O3
� Iron (III) Oxide
� Anion is named second� Monatomic - add “ide” to the stem of the word� Polyatomics – see cheat sheet
� Remember…� Cu can be +1 or +2. Fe can be +2 or +3. So....� Copper (II) means copper with a +2 charge.� Iron (III) means iron with a +3 charge.
� EXAMPLE:
� O -2 = oxide
� S -2 = sulfide
� Br-1 =
� I -1 =
� Name: CuO
� Answer:
� Name: Al2O3
� Answer:
� Name: Ca(OH)2
� Answer:
� Name: FeCl3� Answer:
� Name: Cu(NO3)2
� Answer: