review write the electron configuration for an atom of carbon and chlorine. determine the...
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ReviewWrite the electron configuration for an atom
of carbon and chlorine.Determine the empirical and molecular
formula for a compound consisting of 7.8% carbon and 92.2% chlorine. The molecular mass of the compound is 154 g/mole.
Write the name for the compound.
What is a covalent bond?A covalent bond forms between two atoms that are
sharing one or more pair of electrons.Usually occurs when the electronegativity difference
between the two elements is small (<1.7)Covalent bonds form between two nonmetals.The bond results from an overlapping of orbitals.A covalent bond is a weaker bond than an ionic bond.Properties of compounds resulting from a covalent
bond include: low melting point, gases or liquids at room temp (some are soft solids), do not conduct electricity, many are insoluble in water.
Naming covalently bonded compounds.The first element is named according to the
element name.An –ide ending is added to the name of the
second element.Numerical prefixes are used to indicate the
number of each type of atom present.
Numerical PrefixesPrefix Number*Mono (only used with the second element)
1
Di 2Tri 3Tetra 4Pent 5Hex 6Hept 7Oct 8Non 9Dec 10
Write the formulas for the following compounds:Sulfur trioxideDioxygen difluorideTetraphosphorus decaoxideDiboron trioxideArsenic pentafluorideSilicon dioxideMonohydrogen dioxideNitrogen trihydride
Types of Covalent BondsA single covalent bond occurs when one pair
of electrons (2 electrons) are shared between two atoms.
A double covalent bond occurs when two atoms share two pairs (4 electrons) of electrons.
A triple covalent bond occurs when two atoms share three pairs (6 electrons) of electrons.
Drawing Lewis Dot StructuresLewis dot structures can be drawn to represent
the bonding that occurs within a covalent molecule.
Atoms of hydrogen and halogens can only form one single bond each. (They only need to share 1 electron to form a complete octet).
Lines represent the shared pairs of electrons or the chemical bonds between atoms. Unshared pairs are represented by dots or a line.
For molecules involving atoms other than halogens or hydrogenUse the formula “N-A = S” to determine the
number and type of bonds within the molecule.N represents the total number of valence electrons
needed by all atoms to have a complete octet.A represents the total number of valence electrons
available in all atoms within the molecule.S represents the total number of electrons that
will need to be shared in order to form complete octets for each atom.
Divide the number shared by 2 to determine the number of bonds that will form.
Draw the Lewis dot structure for O2.N= 16A=12S=44/2=2 Therefore, 2 bonds are needed (or 4
electrons need to be shared) in order for this molecule to form.
Draw the Lewis dot structure for N2.Step 1: Solve the equation “N-A = S”Step 2: Divide “S” by 2.Step 3: Draw the general structure of the
molecule Step 4: Fill in the bonds.Step 5: Fill in the remaining valence
electrons so that all atoms have a stable arrangement (8 electrons)
Homework:Name and Draw Lewis Dot Structures for the
following molecules:1) PCl3 7) HCl2) OF2 8) CS23) N2 9) H2CO4) Br2 10) C2H25) O26) SiF4
Polar vs Nonpolar BondsIf the electrons are shared equally, it is called
a nonpolar covalent bond. (This type of bond only occurs if the electrons are shared between identical atoms)
If the electrons are shared unequally, it is called a polar covalent bond.
Polar and Nonpolar MoleculesMolecules can also be polar and nonpolar.Molecules are nonpolar if:
1) the bonds are nonpolar2) the polar bonds are arranged symmetrically
Molecules are polar if the polar bonds are arranged asymmetrically.
In covalent compounds, atoms become stable by ___ their valence electrons.
95%
5% 1. transferring2. sharing
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
A ___ covalent bond is the result of an equal share of electrons by both atoms.
89%
11% 1. polar2. nonpolar
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
A cation has a ___ charge.
0%
100% 1. positive2. negative
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
When an atom ___ electrons, it becomes positively charged.
95%
5% 1. gains2. loses
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
In the formula CO2, the number 2 is called a ___.
100%
0%
0%
0% 1. superscript2. oxidation number3. charge4. subscript
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
What is the correct name for PCl3?
0%
100%
0%
0% 1. Monophosphorus trichloride2. Phosphorus chloride3. Phosphorus trichloride4. Traphosphorus chloride
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
What is the correct name for Li2O?
26%
26%
37%
11% 1. Lithium oxide2. Dilithium oxide3. Lithium (II) oxide4. Lithium dioxide
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
Which is not a diatomic molecule?
56%
11%
22%
11% 1. Fluorine2. Nitrogen3. Bromine4. Boron
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
Which element is a nonmetal?
0%
89%
0%
11% 1. Boron2. Lithium3. Carbon4. Magnesium
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
Which element has 7 valence electrons?
0%
100%
0%
0% 1. Boron2. Nitrogen3. Fluorine4. Manganese
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
Noble gases are stable because they have __ valence electrons.
100%
0%
0%
0% 1. 22. 43. 64. 8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
The noble gases are in which block of the periodic table?
11%
22%
61%
6% 1. s2. p3. d4. f
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
Electrons have what charge?
0%
16%
84% 1. -12. +13. 0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
How many valence electrons are in an atom of oxygen?
0%
100%
0%
0% 1. 22. 43. 64. 8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
How many shared pairs are present?
0%
0%
100%
0% 1. 12. 23. 34. 4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
How many electrons are not shared?
68%
0%
26%
5% 1. 12. 23. 34. 4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
How many single bonds are present?
32%
0%
63%
5% 1. 12. 23. 34. 4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
Are the bonds polar or nonpolar?
26%
74% 1. Polar2. Nonpolar
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
What is the shape of the molecule?
16%
0%
63%
21% 1. Linear2. Bent3. Trigonal pyramidal4. Tetrahedral
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
Is the molecule polar or nonpolar?
37%
63% 1. Polar2. Nonpolar
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
10 ml of the substance has a mass of 9 g. What is its density?
0%
16%
5%
79% 1. 0.9 g/ml2. 1.0 g/ml3. 1.1 g/ml4. 19 g/ml
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
What is the percent oxygen in the substance?
6%
22%
61%
11% 1. 11%2. 33%3. 67%4. 89%
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23
Double and Triple BondsA double covalent bond occurs when two
atoms share two pairs (4 electrons) of electrons.
A triple covalent bond occurs when two atoms share three pairs (6 electrons) of electrons.
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