WHAT TYPE OF BOND DO ALUMINUM AND CHLORINE FORM? AlCl 3.
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Transcript of WHAT TYPE OF BOND DO ALUMINUM AND CHLORINE FORM? AlCl 3.
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
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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