Chapter 6 - Part Two Flashcards
What are most of the rocks and minerals that make up earth’s crust consisted of?
Positive and negative ions held together by ionic bonding
What do most ionic compounds exist as?
Crystalline solids
What is a crystal?
A three-dimensional network of positive and negative ions mutually attracted to each other
What does a chemical formula of an ionic compound represent and how does that differ from molecular compounds?
It represents the simplest ratio of the compound’s ions, not independent, neutral atoms that can be isolated.
What is a formula unit?
The simplest collection of atoms from which an ionic compound’s formula can be established
Ex: NaCl
Why do ions form a crystal lattice and what does that look like?
They want to minimize their potential energy
Attractive forces between opposite charges; repulsive forces between like charges
The combined forces determine the distance between ions and the pattern of their arrangement
What is lattice energy?
The energy released when one mole of an ionic crystalline compound is formed from gaseous ions
Compare the bonds in ionic and covalent compounds
The forces that hold ions together is a very strong electrostatic charge, but the forces of attraction between molecules in a covalent compound are much weaker
What is the general melting point and state of molecular compounds?
Low melting points, exist as liquids and gases
What is the general melting point, state, quality, and ability to conduct electricity (solid and liquid) of ionic compounds?
High melting/boiling points, hard/brittle solids, only good conductors in a liquid state or when dissolved in water
What is a polyatomic ion?
A charged group of covalently bonded atoms
What is different about the energy levels in metals?
The vacant orbitals in the atom’s outer energy levels overlap
Describe the movement electrons in a metal and what they form
They can roam freely because they are delocalized; they form a sea of electrons
What is metallic bonding?
The chemical bonding that results from the attraction between metal atoms and the surrounding sea of elections
What are the four metallic properties and why?
Electrical/thermal conductivity (electrons can move), shiny appearance (electrons jump to a higher energy state, then quickly fall), malleability and ductility (atoms can get close without breaking any bonds)
Describe an molecule with two bonds and no pairs of electrons by electron domain geometry and molecular geometry
Linear/linear
Describe an molecule with three bonds and no pairs of electrons by electron domain geometry and molecular geometry
Trigonal planer/ trigonal planer
Describe an molecule with two bonds and one pair of electrons by electron domain geometry and molecular geometry
Trigonal planer/bent
Describe an molecule with four bonds and no pairs of electrons by electron domain geometry and molecular geometry
Tetrahedral/tetrahedral
Describe an molecule with three bonds and one pair of electrons by electron domain geometry and molecular geometry
Tetrahedral/trigonal pyramidal
Describe an molecule with two bonds and two pairs of electrons by electron domain geometry and molecular geometry
Tetrahedral/bent
What is an ionic compound composed of?
Positive and negative ions that are combined so that the numbers of positive and negative charges are equal
What is molecular polarity?
The uneven distribution of molecular charge
What does VSEPR stand for?
Valence-Shell Electron Pair Repulsion Theory
What does vsepr theory state?
Repulsion between the sets of valence-level electrons surrounding an atom causes these sets to be oriented as far apart as possible
What is steric number?
How many “things” are arranged around the central atom (bonds and lone pairs)
What is electron domain geometry?
A description of how the things are arranged around the central atom (bonds and lone pairs)
What is molecular geometry?
A description of the shape of a molecule based upon the three-dimensional arrangement of the molecules atoms in space (does not include lone pairs)
What is hybridization?
The mixing of two or more atomic orbitals of similar energies on the same atom to produce new hybrid atomic orbitals of equal energies
What are hybrid orbitals?
Orbitals of equal energy produced by the combination of two or more orbitals of the same atom
What are the hybrid orbitals up to the steric number of six?
2-sp,3-spp,4-sppp,5-dsppp,6-ddsppp
What are intermolecular forces?
The forces of attraction between molecules
What does inter mean?
Between
What does intra mean?
Inside
How strong are intermolecular forces in relation to the bonds within molecules, ions in ionic compounds, and metal atoms in solid atoms?
Weaker
What are the four IMFs in order from strongest to weakest?
Ion-dipole forces -> hydrogen bonding -> dipole-dipole forces -> London dispersion forces
How do you measure the strength of IMFs?
The higher the boiling point, the stronger the IMFs
What is the rule about solubility?
Like dissolves like
Polar in polar
Nonpolar in nonpolar
What is a dipole formed from?
Equal but opposite charges that are separated by a short distance
What sort of bonds create dipoles?
Polar
How is a dipole resresented?
An arrow with its head pointing toward the negative pole and a crossed tail at the positive pole
What is molecular polarity?
Whether a molecule has a pole, or a negative side and a positive side
How do you determine molecular polarity?
If the atoms are different there can be polarity, lone pairs mean that it will probably be polar, if the shape does not cancel out the polar bonds then it is polar
What are dipole-dipole forces?
Forces that occur when the negative region in one polar molecule attracts the positive region in adjacent molecules
How can a dipole be induced?
When a polar molecule attracts its electrons
What three atoms can hydrogen bond with to form a hydrogen IMF?
Nitrogen, oxygen, fluorine each with at least one unshared pair
What is hydrogen bonding?
The intermolecular force in which a hydrogen atom that is bonded to a highly electronegative atom is attracted to an unshared pair of electrons of an electronegative atom in a nearby molecule
What are hydrogen bonds represented by?
A dotted line
Where are ion-dipole forces present?
Ions dissolved in a polar solution (water)
What are London dispersal forces and why are they different?
The intermolecular attractions resulting from the constant motion of electrons and the creation of instantaneous dipoles, all atoms even noble gases and non-polar atoms have them
When do London dispersal forces increase?
With increasing atomic or molar mass
EC
Describe an molecule with five bonds by electron domain geometry and molecular geometry
Trigonal Bipryamidal/ “”
EC
Describe an molecule with four bonds and one pair of electrons by electron domain geometry and molecular geometry
Trigonal Bipryamidal/seesaw
EC
Describe an molecule with three bonds and two pairs of electrons by electron domain geometry and molecular geometry
Trigonal Bipryamidal/T shaped
EC
Describe an molecule with two bonds and three pairs of electrons by electron domain geometry and molecular geometry
Trigonal Bipryamidal/linear
EC
Describe an molecule with six bonds by electron domain geometry and molecular geometry
Octahedral/ “”
EC
Describe an molecule with five bonds and one pair of electrons by electron domain geometry and molecular geometry
Octahedral/square pyramidal
EC
Describe an molecule with four bonds and two pairs of electrons by electron domain geometry and molecular geometry
Octahedral/square planer
EC
Describe the maximum angles for molecules with steric numbers of 2, 3, 4, 5, and 6
180, 120, 109.5, 120 and 90, 90
Are hydrocarbons (H and C) usually polar or nonpolar?
Nonpolar
Are alcohols (O and H) usually polar or nonpolar?
Polar
