Gen Chem 1 - Ch 9 & 10
The molecule HCN (C is the central atom) has 1. 2 sigma and 2 pi bonds. 2. 1 sigma and 3 pi bonds. 3. 4 sigma bonds. 4. 2 sigma bonds. 5. 2 sigma and 1 pi bond.
1. 2 sigma and 2 pi bonds.
The Lewis structure for N2H2 (HHNH) shows 1. two single bonds, one double bond and two unshared pairs 2. three single bonds and four unshared pairs 3. three single bonds and two unshared pairs 4. two single bonds, one double bond and dour unshared pairs
1. two single bonds, one double bond and two unshared pairs
Tetrahedral bond angle for electron group 4
109.5°
Trigonal Planar bond angle for electron group 3
120°
Trigonal Bipyramidal bond angle for electron group 5
120° Equatorial, 90° Axial
Linear bond angle for electron group 2
180°
Linear bond angle for electron group 5
180°
Which of the following about NO2+ is correct? 1. The ion has no sigma bonds and two pi bonds. 2. The ion had two sigma bonds and two pi bonds. 3. The ion had four pi bonds 4. The ion has two sigma bonds and one pi bond.
2. The ion had two sigma bonds and two pi bonds.
How many σ and π bonds are there in the molecule below? ````` .. H-C≡C-N-H ````` | ````` H 1. 7 σ, 1 π 2. 6 σ, 2 π 3. 5 σ, 1 π 4. 6 σ, 1 π
3. 5 σ, 1 π
Octahedral bond angle for electron group 6
90°
Square Planar bond angle for electron group 6
90°
Bent bond angle for electron group 4
<109.5°
Trigonal Pyramidal bond angle for electron group 4
<109.5°
Bent bond angle for electron group 3
<120°
See-saw bond angle for electron group 5
<120° Equatorial, <90° Axial
Square Pyramidal bond angle for electron group 6
<90°
T-shaped bond angle for electron group 5
<90°
Polar covalent bond
A covalent bond with greater electron density around one of the two atoms. NOT the same two non-metals
Linear
AB2 and No lone pairs
Bent
AB2E or AB2E2
Trigonal Planar
AB3, No lone pairs, 120 degree angles
Trigonal Pyramidal
AB3E
T-Shaped
AB3E2
Tetrahedral
AB4, No lone pairs, 109.5 degree angles
Square Planar
AB4E2
Trigonal Bipyramidal
AB5, No lone pairs, 120 and 90 degree angles
Square Pyramidal
AB5E
Octahedral
AB6, No lone pairs, 90 degree angles.
Octet Rule
An Atom other than H tends to form bonds until it is surrounded by 8 valence electrons.
Electronegativity
An atom's ability attract electrons towards itself in a chemical bond.
Molecular geometry with 2 bonding groups and 1 lone pair
Bent
Molecular geometry with 2 bonding groups and 2 lone pairs
Bent
Covalent Bonds
Bond which two electrons are shared by two atoms
Lewis Dot Symbol
Consist of an element and one dot of each valance electron in an atom
Expanded Octet
Elements in and beyond the 3rd period can have more than 8 electrons around them.
Incomplete Octet
Elements that tend to form compounds in which they are surrounded by fewer than 8 electrons have an
Molecular geometry with 2 bonding groups and 0 lone pairs
Linear
Molecular geometry with 2 bonding groups and 3 lone pairs
Linear
Molecular geometry with two electron groups
Linear
Molecular geometry with 6 bonding groups and 0 lone pairs
Octahedral
Molecular geometry with six electron groups
Octahedral
Molecular geometry with 4 bonding groups and 1 lone pair
See-saw
Odd-Electron Molecules
Some molecules have an odd number of electrons, so octet cannot be satisfied for all atoms.
Molecular geometry with 4 bonding groups and 2 lone pairs
Square Planar
Molecular geometry with 5 bonding groups and 1 lone pairs
Square Pyramidal
Molecular geometry with 3 bonding groups and 2 lone pairs
T-shaped
Molecular geometry with 4 bonding groups and 0 lone pairs
Tetrahedral
Molecular geometry with four electron groups
Tetrahedral
Formal charge
The charge difference between valence electrons and the number of electrons assigned in a Lewis structure.
Ionic Bond
The electrostatic force that holds ions together in an ionic compound.
Lattice energy
The energy required to completely separate one mole of a solid ionic compound into gaseous ions. E=k((Q+Q-)/r)
Resonance
The use of two or more Lewis structures to represent a particular molecule
Molecular geometry with 5 bonding groups and 0 lone pairs
Trigonal Bipyramidal
Molecular geometry with five electron groups
Trigonal Bipyramidal
Molecular geometry with 3 bonding groups and 0 lone pairs
Trigonal Planar
Molecular geometry with three electron groups
Trigonal Planar
Molecular geometry with 3 bonding groups and 1 lone pair
Trigonal Pyramidal
Which of the following hydrocarbons have two π bonds? a. C3H4 b. C4H8 c. C6H12 d. C7H14 e. C8H18
a. C3H4
Which of the following compounds is expected to have the strongest ionic bond? a. MgO b. KBr c. NaI d. SrO e. CaS
a. MgO
Hybrid orbitals
atomic orbitals obtained when two or more nonequivalent orbitals of the same atom combine in preparation for covalent bond formation
Valence bond theory
bonds form due to the overlapping of atomic orbitals
The lattice energy of KF is -821 kJ/mol. This energy corresponds to which reaction below? a. K(s) + 1/2 F2(g) → KF(s) b. K(g) + F(g) → KF(s) c. K+(g) + F-(g) → KF(s) d. K+(aq) + F-(aq) → KF(s)
c. K+(g) + F-(g) → KF(s)
Pi bond (π bond)
covalent bond formed by sideways overlapping orbitals with electron density concentrated above and below the plane of the nuclei of the bonding atoms
Sigma bonds (σ bonds)
covalent bonds formed by orbitals overlapping end-to end, with electron density concentrated between the nuclei of the bonding atoms.
The type of compound that is most likely to contain a covalent bond is which of the following? a. one that is composed of a metal from the far left of the periodic table and a nonmetal from the far right of the periodic table b. a solid metal c. a substance held together by the electrostatic forces between oppositely charged ions d. one that is composed of two nonmetals e. there is no general rule to predict covalency in bonds
d. one that is composed of two nonmetals
Polyatomic molecules
form covalent bonds through the overlap of hybrid orbitals
Hybridization
the mixing of atomic orbitals in an atom (usually a central atom) to generate a set of hybrid orbitals.
Dipole Moments
used to determine whether or not a molecule is polar or non-polar