Lab Teams – Chem T 1AStation 1- Steven V, Max, Amulya, Kahdijah
Station 2- Chuck, Gabby, Tanay, Jas-Lynn
Station 3- Danyal, Sanya, Moe, Frances Station 4- Steven T, Julia, Jarar, Rahul, Elsu Station 5- Taran, Athul, Rohan, Ben
Station 6- Manasa, Russell, Trishi, Matt
Lab Teams - Chem T 2AStation 1- Manav, Hannah, Jaylend, Pooja
Station 2- Kenny, Fatumo, Ally, Jack
Station 3- Andrea, Abdul-Ahad, Amanda
Station 4- Kevin, Sam, Kailey
Station 5- Peter, Hussain, Anthony, Dhruv
Station 6- Janae, Jonathan, Samvit, Nidhi
Charges of Ions, Naming Ionic Compounds
Atoms have NO overall charge• Atoms are not charged, even though they are made up
of charged particles
• Atoms have an equal number of protons (positive charge) and electrons (neg. charge) whose charges exactly cancel.
• Ex: Helium (He)– 2 protons, 2 neutrons, 2 electrons
+2 0 -2 = 0 total charge
Why do atoms bond??
• Atoms bond to be more stable!!
• Atoms join to form bonds so that each atom has a full outermost energy level – by either sharing or transferring electrons
• What is the number of electrons that atoms want to have in their outermost shell?
Ionic Bonds•Ionic bonds are formed
between oppositelycharged ions.
Ionic bonds are formed by the transfer of electrons
•Ionic bonds exist between metal and non-metal and are called Ionic Compounds
Covalent Bonds•Covalent bonds are formed by the
sharing of electrons between atoms
Covalent Bonds exist between non-metals and are called molecular compounds
Atoms gain or lose electrons to become IONS
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Some Atoms Form Ions•An ion is an atom or group of atoms that has lost or
gained one or more electrons and has a net negative or positive charge.• A lithium atom loses one electron to form a 1+ charged ion:
• A fluorine atom gains one electron to form a -1 charged ion:
Chapter menu
Resources
Formation of Ions
• Cation: an atom loses one or more electrons and becomes positively charged
Na – 1 electron Na+
• Anion: an atom gains one or more electrons and becomes negatively charged
Cl + 1 electron Cl-
+ +
When will an element form a cation? When will an element form an anion?• An element wants to be stable. A stable electron
arrangement is one with eight electrons in the valence (or outer) shell.
Barium = 2 valence e- = Ba2+ cation
Iodine = 7 valence e- =I- anion
What is the charge on the ions of the following elements? Hint: Use your Periodic Table!!
• Sodium• Magnesium• Fluorine• Oxygen• Cesium• Phosphorus• Aluminum
OK Cool, Now that we know that..
Writing and Naming Ionic Formulas
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Objectives
•Name simple ionic compounds.
•Write chemical formulas for simple ionic compounds.
Chapter menu Resources
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Chapter menu Resources
Writing Ionic FormulasWhat is the chemical formula for aluminum fluoride?
1.List the elemental symbols for each ion (with the cation first)
2. Write the charges as superscripts for each ion.
3.Criss-cross values of charges
4.Write the chemical formula, indicating with subscripts how many of each ion are needed to make a neutral compound.
What is the formula for the compound made of Ca2+ cations and Cl1- anions?
Total charges of possible formulas are shown:
CaCl: 1Ca2+ + 1 Cl1- (2+) + (1-) = 1+Ca2Cl: 2 Ca2+ + 1 Cl1- (2+) + (2+) + (1-) = 4+CaCl2: 1 Ca2+ + 2 Cl1- (2+) + (1-) + (1-) = 0
The only formula that is neutral is CaCl2
Use the crisscross method to find the formula of an ionic compound
1. Write the cation and anion symbols with ionic charges. For calcium chloride,Ca2+ Cl1-
2. Make the number in the positive charge into a subscript for the anion. Make the number in the negative charge into a subscript for the cation. Ignore the – and + signsCa2+ Cl1-
Ca 1 Cl 2 = CaCl2
3. If necessary, reduce the resulting formula to its smallest whole-number ratio. To do this, divide all subscripts by the largest common factor
What is the formula for the compound made of Mg2+ cations and Br1- anions?
What is the formula for the compound made of Al3+ cations and S2- anions?
Practice
• Write ionic formulas for the following ionic compounds:
• Lithium oxide• Beryllium chloride• Magnesium oxide• Sodium Chloride• Lithium Nitrate• Aluminum Sulfide
Naming Binary Ionic Compounds• There are two types of binary ionic compounds:
– Type I: Metal only forms one cation (not a transition metal)– Type 2: Metal can form two (or more) cations that have different charges
(transition metal)
• Naming Type I Binary Compounds– Name the cation first and the anion second– Replace the ending of the anion with –ide to it.
• Examples:– NaCl
• Sodium Chloride– CaO
• Calcium Oxide
– ZnCl2 • Zinc Chloride
Important!!
• Some metal atoms form ions with different charges under different conditions. To specify the charge for these ions, Roman numerals are used in parentheses after the name of the metal. These include: copper, lead, iron, mercury.
• Check your ion reference sheet!!
Naming Binary Ionic Compounds with Cations of Varying Charge
– Name the cation first – Write charge of cation as roman numeral in parentheses– Anion with the –ide ending
• Fe2O3
– Iron (III) Oxide• AuCl– Gold (1) Chloride
• CuBr2
• Copper (II) Bromide
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Naming Binary Ionic Compounds – Ions of varying chargeSome cation names must show their charge.
• Iron can form two different cations. Fe2O3 is made of
Fe3+ ions, so it is named iron(III)oxide. FeO is made of Fe2+ ions, so it is named iron(II) oxide.
To determine the charge of a transition metal cation,look at the total charge of the compound.
• You can tell that the iron ion in Fe2O3 has a charge of 3+
because the total charge of the compound must be zero, and an oxide ion, O2–, has a a charge of 2–.Chapter menu Resources
Try these!
• CuCl• CuCl2
• PbF2
• PbF4
Write the Formula for Binary Ionic Compounds with Transition Metals
Iron (111) Sulfide
Tin (11) Chloride
Copper(1)Oxide
Tin (1V) Oxide
Tin(11) Oxide
Naming Tertiary Compounds
• Naming Tertiary Ionic Compounds– Name cation– Indicate the charge if cation has varying charges– Name the polyatomic ion
A polyatomic ion is a group of two or more atoms covalently bonded or metallically bonded together to function as a single ion (has a charge associated with it).
An example being the hydroxide ion, OH-. The oxygen and hydrogen are covalently bonded together, and function as a single anion with a 1- charge.
Polyatomic IonsBrO3
- bromate
IO3- iodate
CO2-2 carbonite
Naming Tertiary Ionic Compounds• Check if the cation requires that you show charge• Name cation• Name anion (polyatomic)
• Examples– Na2SO4
– Fe(NO3)3
– (NH4 )OH
– Cu(NO2)2
Writing Formulas for Tertiary Ionic Compounds
Potassium Hydroxide
Magnesium Sulfate
Iron (111) Nitrate
Zinc (11) Phosphate
CaBr2
SnO
Pb(CO3)2
WRITE THE CHEMICAL FORMULA
Don’t use parentheses unless necessary
Mercury (II) sulfide
Cobalt (III) nitrate
Magnesium phosphate
Tin (II) Nitride
Copper (I) Sulfide