Properties of Ionic Compounds Forming NaCl from Na and Cl 2 • A metal atom can transfer an electron to a nonmetal. • The resulting cation and anion are attracted to each other by electrostatic forces.
Dec 28, 2015
Properties of Ionic CompoundsForming NaCl from Na and Cl2
Properties of Ionic CompoundsForming NaCl from Na and Cl2
• A metal atom can transfer an electron to a nonmetal.
• The resulting cation and anion are attracted to each other by electrostatic forces.
The Octet Rule – Ionic Compounds
Ionic compounds tend to form so that each atom, by gaining or losing electrons, has an electron arrangement like that of a noble gas.
CATION + ANION --->
COMPOUND
CATION + ANION --->
COMPOUND
A neutral compound requires
equal number of + and - charges.
A neutral compound requires
equal number of + and - charges.
COMPOUNDS FORMED
FROM IONS
COMPOUNDS FORMED
FROM IONSNa+ + Cl- --> NaCl
Electron Dot Notation
Predicting Ionic Charges
Group 1:Lose 1 electron to form 1+ ions
H+ Li+ Na+ K+
Predicting Ionic Charges
Group 2:Loses 2 electrons to form 2+ ions
Be2+ Mg2+ Ca2+ Sr2+ Ba2+
Predicting Ionic ChargesGroup 13: Loses 3 electrons to form 3+ ions
B3+ Al3+ Ga3+
Predicting Ionic ChargesGroup 14: Loses 4 electrons or gains 4 electrons
Caution! C22- and C4-
are both called carbide
Predicting Ionic ChargesGroup 15: Gains 3 electrons to form 3- ions
N3-
P3-
As3-
Nitride
Phosphide
Arsenide
Predicting Ionic ChargesGroup 16: Gains 2 electrons to form 2- ions
O2-
S2-
Se2-
Oxide
Sulfide
Selenide
Predicting Ionic ChargesGroup 17: Gains 1 electron to form 1- ions
F1-
Cl1-
Br1-Fluoride
Chloride
Bromide
I1- Iodide
Predicting Ionic ChargesGroup 18: Stable Noble gases do not form ions!
Predicting Ionic ChargesGroups 3 - 12:
Many transition elements have more than one possible oxidation state.Iron(II) = Fe2+ Iron(III) = Fe3+
Predicting Ionic ChargesGroups 3 - 12:
Some transition elements have only one possible oxidation state.
Zinc = Zn2+ Silver = Ag+
Predicting Charges on Monatomic IonsKNOW THESE !!!!
+1 +2 -3 -2 -1 0
Be2+
Writing Ionic Compound Formulas
Example: Iron(III) chloride
1. Write the formulas for the cation and anion, including CHARGES!
Fe3+Cl-2. Check to see if charges are balanced.
3. Balance charges , if necessary, using subscripts.
Not balanced!
3
Writing Ionic Compound Formulas
Example: Aluminum sulfide
1. Write the formulas for the cation and anion, including CHARGES!
Al3+ S2-2. Check to see if charges are balanced.
3. Balance charges , if necessary, using subscripts. Not
balanced!
2 3
Formulas of Ionic Compounds
Formulas of ionic compounds are determined from the charges on the ions
atoms ions
–Na + F : Na+ : F : NaF
sodium + fluorine sodium fluoride formula
Charge balance: 1+ 1- = 0
Some Ionic CompoundsSome Ionic Compounds
Mg2+ + N-3 ---->Mg3N2
magnesium nitrideSn4+ + O2- ----> SnO2
Tin (IV) oxide
calcium fluoride
Ca2+ + 2 F- CaF2
Monatomic Ions
Learning Check
Write the correct formula for the compounds containing the following ions:1. Na+, S2-
a) NaS b) Na2S c) NaS2
2. Al3+, Cl-
a) AlCl3 b) AlCl c) Al3Cl
3. Mg2+, N3-
a) MgN b) Mg2N3 c) Mg3N2
Solution
1. Na+, S2-
b) Na2S
2. Al3+, Cl-
a) AlCl3
3. Mg2+, N3-
c) Mg3N2