Chemistry Chapter 4/5 Quiz

Ionic bond

Bond resulting from electrostatic attraction between an anion and cation

Electrons in an ionic bond

Transferred from one atom to another

Elements involved in ionic bonds

Metals and nonmetals

Covalent bond

A bond resulting from sharing valence electrons

Elements involved in covalent bonds

Nonmetals and/or metalloids

Polar covalent bond

A covalent bond that is a result of unequal sharing of electrons and creates an unequal charge distribution

Stronger vs weaker atoms in polar covalent bonds

Stronger atoms steal more electrons and end up slightly negative and weaker atoms end up slightly positive

Non-polar covalent bond

A covalent bond where all electrons are shared equally

How is bond polarity determined

By finding the differenceM in electronegativity

Metallic bond

A bond that involves a metal atom surrounded by shared electrons

Why are metallic bonds good conductors

Because their bonds are very ordered and current travels the structure easily

Electronegativity

The ability of an atom in a bond to attract electronsT

Trend of electronegativity

Increases from left → right, increases bottom → top

Non-polar value

0.0

Essentially non-polar value

0.0 - 0.4

Polar covalent value

0.4 - 1.8

Ionic bond value

>1.8

Polyatomic ions

Charged ions with two or more atoms joined together by covalent bonds

Acetate

CH₃COO⁻

Bicarbonate

HCO₃⁻

Carbonate

CO₃²⁻

Hydroxide

OH⁻

Perchlorate

ClO₄⁻

Hypochlorite

ClO⁻

Permanganate

MnO₄⁻

Nitrate

NO₃⁻

Nitrite

NO₂⁻

Phosphate

PO₄³⁻

Sulfate

SO₄²⁻

Ammonium

NH₄⁺

Cyanide

CN⁻

What did Lewis discover in 1916

Atoms form chemical bonds by sharing electrons to gain noble gas configuration

Who loses/gains electrons in ionic compounds

Metals lose electrons, nonmetals gain electrons

Bond order

Number of bonds between two atoms

Bond energy

Energy required to break one mole of bonds

How are bond order and bond energy related

Higher bond order = higher bond energy

How does energy change when bonds are formed or broken

Forming bonds releases energy, breaking them consumes energy

Bond length

The distance from one atom to the next in a bond

How are bond order and bond length related

Higher bond order = shorter bond length

Formal charge equation

Valence electrons - lone pairs - bonding electrons/2

What is the relationship between electronegativity and formal charge

More electronegative elements should have a negative FC

Valence shell electron pair repulsion theory (VSEPR)

Model that lets us predict a molecules shape with lone pairs and bonding atoms to minimize repulsion

Electron pair geometry

3D arrangement of bonding atoms and lone pairs

Molecular geometry

3D arrangement of just bonding atoms

Steric number equation

Atoms bonded to central atom + lone pairs on central atom

Bond angle

The angle from joining the centers of three covalently bonded atoms

What bond has the greatest repulsion

Lone pair - lone pair

What bond has the least repulsion

Atom - atom

Dipole moment

Expression of the polarity of a molecule

What does the sum of dipole vectors tell us

If the sum of them is greater than zero, the bonds are polar

Valence bond theory

The overlap of ½ filled orbitals to give a pair of shared electrons can form sigma and pi bonds

Which type of valence bond has electron density on the internuclear axis

Sigma bonds

What does hybridization do

It minimizes the total amount of energy needed to bond

What hybridization has a steric number of 2

sp

What hybridization has a steric number of 3

sp²

What hybridization has a steric number of 4

sp³

What hybridization has a steric number of 5

sp³d

What hybridization has a steric number of 6

sp³d²