CHM 103: Chapter 4
35 Cards in this Set
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ionization energy
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the energy required to remove an electron from the atom in the gas phase; it takes more energy each subsequent electron because the electrons closer to the proton are held more strongly towards the nucleus; increases from left to right; decreases from top to bottom
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Electronegativity
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A measure of an elements attraction for the electrons it shares with another element in a covalent bond.
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Covalent Bonding
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Sharing of valence electrons between non-metal elements
(strong bond)
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What is an ion?
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A charged atom/molecule. Its charged either neg or pos depending on whether an atom gains or loses an electron (gains = - ... lose = +)
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What are the two ways atoms can achieve the stability of a noble gas electron configuration?
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gaining / losing electrons to become ions;
sharing electrons / forming covalent bonds
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Isoelectronic
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atoms/ions that have the same number of electrons (different mass numbers).
radii decrease with increasing atomic number because of increasing nuclear charge (more p+ to e-).
more p+ in nucleus = greater electrostatic potential with the e'
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Ionic Compound
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A compound composed of positive and negative charged ions held together by electrostatic attraction
---number of positive and negative ions are equal to produce a neutral group of ions
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molecular compound
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Covalent bonds (between nonmetals)
--CO2 where O2 is a molecular element
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What is group 4A's (Carbon) covalent bonding patterns?
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0 lone pairs
4 bonds needed
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What is group 5A's covalent bonding patterns?
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1 lone pair
3 bonds needed
(N,P)
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What is group 6A's covalent bonding patterns?
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2 lone pairs
2 bonds needed
(O, S, Se)
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2 lone pairs
2 bonds needed
(O, S, Se)
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2 lone pairs
2 bonds needed
(O, S, Se)
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What is group 8A's covalent bonding patterns?
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These are the noble gases!
No bonds are necessary, naturally have a full valence shell
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electron group
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either:
1) a bonding electron group (i.e. a single bond, a double bond, or a triple bond)
2) a nonbonding electron group (i.e. a non bonding pair (aka a lone pair))
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Molecular Geometry
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arrangement of bonded atoms
2 e groups = linear
3 = trigonal planar
4 = tetrahedral
5 = trigonal bipyramidal
6 = octahedral
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Electron Geometry
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Linear...O=C=O
Trigonal Planar... 3 atoms that are bent but in same plane.
Tetrahedral... 4 atoms/ 3 atoms & 1 lone pair/ 2 atoms & 2 lone pairs.
[[[based on # of electron groups]]]
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What is the Electron Group Geometry of the carbon atom labeled #6?
What is the Molecular Group Geometry?
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--->Carbon #6 has THREE groups of electrons:
2 single bonds (to the C to its left, & to the H atom)
1 double bond (to the carbon to its right).
Three groups of electrons = trigonal planar electron group geometry.
--->Since there is an atom in all 3 corners of the triangle, the mol…
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What is the Electron Group Geometry of the Fluorine atom labeled #9?
What is the Molecular Group Geometry?
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The fluorine atom has FOUR groups of electrons:
1 single bond (the carbon atom to its left), and
3 lone pairs of electrons (which are not drawn, but are understood to be there).
Four groups of electrons = tetrahedral electron group geometry.
The fluorine's molecular geometry would…
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What is the Electron Group Geometry of the Nitrogen atom labeled #4?
What is the Molecular Group Geometry?
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The nitrogen atom has FOUR groups of electrons:
3 SINGLE BONDS (to the H & the C on the right, and the C in the ring), and
1 LONE PAIR (not drawn, understood to be there).
Four groups of e- = Tetrahedral e- group geometry.
The N atom's molecular geometry would be trigonal pyramid (w…
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What is the Electron Group Geometry of the Oxygen atom labeled #1?
What is the Molecular Group Geometry?
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The oxygen atom has FOUR groups of electrons:
2 SINGLE BONDS (to the H and C atoms), and
2 LONE PAIRS (understood to be there).
Four groups of electrons = tetrahedral electron group geometry.
The O atom's molecular geometry would be bent -- just like the oxygen atom in a water molec…
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How would an Alkaline Earth metal achieve the stability of a noble gas electron configuration when reacting with a non-metal element to form an ionic compound?
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How would an Alkaline Earth metal achieve the stability of a noble gas electron configuration when reacting with a non-metal element to form an ionic compound?
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How would a Halogen achieve the stability of a noble gas electron configuration when reacting with a metal atom to form an ionic compound?
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gain 1 electron -->become anion with 1- charge
(these will be more electronegative to their metal counterparts and so will steal that 1 missing electron to achieve an octet)
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Consider the ionic compound that forms when calcium metal chemically combines with the non-metal phosphorus.
What is the chemical formula for that ionic compound?
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Ca+2+ P-3
to make balanced find GCF so,
Ca3P2
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Ca+2+ P-3
to make balanced find GCF so,
Ca3P2
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+3
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Consider the chemical formula: CH5N.
The total number of valence electrons that should appear in the Lewis Structure for this molecule is:
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Consider the chemical formula: CH5N.
The total number of valence electrons that should appear in the Lewis Structure for this molecule is:
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Which of the following molecular compounds would have a Lewis Structure that contains a total of 10 valence electrons?
A. NH3
B. HCN
C. H2O
D. CH3Cl
E. CO2
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B. HCN
1 H atom: 1 valence e-
1 C atom: 4 valence e-
1 N atom: 5 valence e-
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diatomic
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elements that exist as bonded pairs when they aren't bonded with other atoms
H, N, O, F, Cl, Br, I
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TRUE OR FALSE
For the Representative Elements (also known as the "Main Group" Elements), the Group Number is equal to the number of valence electrons.
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TRUE
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How to name ionic compounds
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The metal comes first and keeps its name.
The second non-metal element replaces its ending with "ide"
NO PREFIXES -->omit ion and how many appear
If multiple oxidation states, put roman numeral
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How to name covalent bonds?
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--->The prefixes used are mono-, di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, deca-.
--->The mono- prefix is usually not used for the first element in the formula.
--->The "o" and "a" endings of these prefixes are dropped when they are attached to "oxide."
--->2nd element (s…
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If the electronegativity difference between two elements is 2.5, what type of bond is likely to form when atoms of those elements chemically combine to form a compound?
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an ionic bond
[it's a huge mismatch]
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polar covalent bond
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two nonmetal atoms with very different electronegativities share electrons
--electrons are not shared equally
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nonpolar covalent bond
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a covalent bond with a very small difference in electronegativity between the bonded atoms
--electrons are shared equally
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Draw the Lewis structure of ethane, C2H6.
What is the molecular geometry (as opposed to the electron group geometry) of each carbon atom in this molecule?
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CH3-CH3
tetrahedral
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Draw the Lewis structure for C2H2 (acetylene).
What is the molecular geometry (as opposed to the electron-group geometry) of each carbon atom in this molecule?
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H-C---C-H
linear
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CHM 103: Chapter 4