properties of ionic compounds forming nacl from na and cl 2 a metal atom can transfer an electron to...
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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