what type of bond do aluminum and chlorine form? alcl 3
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Aluminum Chloride
WHAT TYPE OF BOND DO ALUMINUM AND CHLORINE FORM?AlCl3
Aluminum Chloride
WHAT TYPE Of BOND DO ALUMINUM AND CHLORINE FORM?
Ionic: Metal and NonMetal
AlCl3
Aluminum Chloride
WHAT TYPE Of BOND DO ALUMINUM AND CHLORINE FORM?
Ionic: Metal and NonMetal
COVALENT BOND
AlCl3
Confused?
To muddy waters even further, there is no such thing as a purely ionic or covalent bond.AlCl3
Electronegativity
--
-- -
-
-
-
-
- -+11A measure of an atom or group of atom’s tendency to attract electrons
As you go across a period Electronegativity increases.
As you go down a group Electronegativity
decreases.
Additional Electron shielding and increased distance from the nucleus makes adding a new electron more difficult
Increasing nuclear charge (pull) without any additional shielding makes makes adding an electron easier.
Electronegativity (χ) is a “rule of thumb”Bond type is to Δ∝ χ
Δ Electronegativity
ELECTRON TUG OF WAR!
Electron Tug of WarH-H Hydrogen 2.20H-F Fluorine 3.98
Electronegativity Sliding Bond Scale
Δχ Bond Type Example
0.0-0.5 Non-Polar Covalent H2
≥0.5 to >1 Polar Covalent HCl
≥1 to <2 Very Polar Covalent HF
≥2 Ionic Bond Na+Cl-
Electron Tug of War
NaClH2OCO2
Water is a Polar Molecule!
Drops on a PennySnapping DropsSurface Tension
Sand vs SnowmanCapillary ActionMelting PointsBoiling Points
Solubility
H2O
Oxygen 3.44Hydrogen 2.20
Carbon Dioxide is Non-Polar
Why is Carbon dioxide non-polar?
CO2
Oxygen 3.44Carbon 2.55Δχ=0.89OO C
Carbon Dioxide is Non-Polar
Why is Carbon dioxide non-polar?
CO2
Oxygen 3.44Carbon 2.55Δχ=0.89OO C
δ+δ- δ-
Because it is linear or perfectly symmetrical.
Carbon Dioxide is Non-Polar
Why is Carbon dioxide non-polar?
CO2
Oxygen 3.44Carbon 2.55Δχ=0.89OO C
δ+δ- δ-
Because it is linear or perfectly symmetrical.
O
Water is Bent
Why is Water Polar?HHδ+δ+
δ-
Because water is not a linear molecule.
O
MOLECULAR GEOMETRY: VSEPR
Why is Water Polar?HH
δ-
δ+ δ+
Because water is not a linear molecule.
What about HCN?
Prussic Acid is Polar
CO2
Hydrogen 2.20Carbon 2.55NitrogenNH C
δ+ δ-
Because it is linear but the ends have opposite charges.
Two types of Covalent Bonds
Non-Polar Covalent• Electrons Shared Equally:• --all diatomic molecules
Polar-Covalent• Electrons Shared Unequally• --due to electronegativity
δ Small Delta indicates PARTIAL CHARGES
There is a small degree of sharing and orbital overlap even in ionic bonds.
Practice ProblemsWhat type of bond will form between the following atoms?
a) N and Hb) F and F
c) Ca and Cld) Al and Cle) H and Brf) K and Clg) C and Oh) Cl and Fi) Li and Oj) H and O
Δ Electronegativity Bond Type0.0-0.5 Non-Polar Covalent
≥0.5 to >1 Polar Covalent≥1 to <2 Very Polar Covalent
≥2 Ionic Bond (Extremely Polar)
Practice ProblemsWhat type of bond will form between the following atoms? a) N (3) and H (2.1) = 0.9 mod PCb) F (4) and F(4) = 0 = non-polar
c) Ca (1) and Cl (3) = 2 = Ionicd) Al (1.5) and Cl (3) = 1.5 = very PCe) H and Br mod PCf) K and Cl ionic g) C and O mod to very PCh) Cl and F mod to very PCi) Li and O ionicj) H and O polar (thisH20!)
Place these covalent bonds in order of least to most polar.
• H—CL• H—Br• H—S• H—C
Answer: C and D tie to B to A