Reactions and Bonding 2
Nov 16 and 17
Agenda Nov 17, 2016
Slip quiz
Check Metallic bonding notes
Ions Pogil - quick check
Ionic Bonding - notes
Naming Ionic Compounds Pogil
(Quick look at Unit 3 test)
1. Write out the correct statement only.
Slip Quiz
a) Metals make negative anions and nonmetals make positive
cations.
b) Metals make positive cations and nonmetals make negative
anions.
c) Metals make negative cations and nonmetals make positive
anions.
d) Metals make positive anions and nonmetals make negative
cations.
2. What is the charge on an ion with 21 protons, 25 neutrons and
18 electrons? a) 4+
b) 3+
c) 4d) 4+
1. Write out the correct statement only.
Slip Quiz
b) Metals make positive cations and nonmetals make negative
anions.
2. What is the charge on an ion with 21 protons, 25 neutrons and
18 electrons?
21protons (21+)
18 electrons (18-)
21 - 18 = 3
1. Write out the correct statement only.
Slip Quiz
b) Metals make positive cations and nonmetals make negative
anions.
2. What is the charge on an ion with 21 protons, 25 neutrons and
18 electrons?
b) 3+
21protons (21+)
18 electrons (18-)
21 - 18 = 3
From last time - write this somewhere for your future
reference
5. Define precision for scientific
measurements.
Precision of measurements refers to how
close to each other a set of measurements
are. Precise measurements show little
variation (but may all be inaccurate). pages
Metallic Bonding Notes - hold them up for credit.
Should include at least one diagram to show
electron sea model
From class slides
One diagram for substitutional alloys
One diagram for interstitial alloys
Metal/
nonmetal?
Number of
protons the
same in
atom and the
ion?
Number of
neutrons
same in the
atom and the
ion?
Number of
Charge on
electrons
the ion
same in the
atom and the
ion?
Lithium
metal
yes
yes
no
1+
Magnesium
metal
yes
yes
no
2+
Aluminum
metal
yes
yes
no
3+
Fluorine
nonmetal yes
yes
no
1-
Oxygen
nonmetal yes
yes
no
2-
Nitrogen
nonmetal yes
yes
no
3-
2) What distinguishes a neutral atom from an
ion?
2) What distinguishes a neutral atom from an
ion?
A change in the number of electrons.
3) a) Where is the ion charge located in the
isotope symbol?
3) a) Where is the ion charge located in the
isotope symbol? Upper right hand corner of
symbol.
3) b) Is the charge indicated in neutral atoms?
If yes, where is it located. There is no charge
shown for neutral atoms.
4. Which subatomic particle carries a positive
charge? Proton.
5. Which subatomic particle carries a negative
charge? Electron.
6. Propose a mathematical equation to
calculate the charge on an ion from the
number of protons and electrons in an ion.
Confirm using 2 positive ion examples and two
negative ion examples.
Number of protons - number of electrons =
charge on ion.
Li1+
3protons - 2 electrons = 1+
Number of protons - number of electrons =
charge on ion.
Li1+
Mg2+
3protons - 2 electrons = 1+
12protons - 10 electrons = 2+
F1-
9protons - 10 electrons = 1-
O2-
8protons - 10 electrons = 2-
Chemists refer to positively charged
ions as cations. Chemists refer to
negatively charge ions as anions.
“Cat”ions are “Paws” ative!
Check your table is completed correctly.
88
Symbol
38
Sr2+
32
16
S2–
70
31
Ga3+
80
35
Br –
Atomic Number
38
16
31
35
Mass number
88
32
70
80
Number of
protons
38
16
31
35
Number of
electrons
36
18
28
36
Number of
neutrons
50
16
39
45
Cation or anion
cation
anion
cation
anion
8. Could a +3 ion of aluminum be made by
adding 3 protons to an aluminum atom?
Explain.
If we added 3 protons to an aluminum atom,
...
8. Could a +3 ion of aluminum be made by
adding 3 protons to an aluminum atom?
Explain.
If we added 3 protons to an aluminum atom,
it would now have a new atomic number
(defined as the number of protons in a
nucleus) - it would become a sulfur atom
(atomic number 16). So, no, we cannot make
a +3 aluminum atom by adding 3 protons.
9. “When you add an electron, you get a
positive charge because adding is positive in
math.” Why is this statement misleading and
incorrect?
When you add an electron you get a
negatively charge ion.
You are adding a particle with a negative
charge, which is like adding a negative
number in a math problem.
11. a) In general, do nonmetals form anions or
cations?
Nonmetals generally form
11. a) In general, do metals form anions or
cations?
Metals generally form
11. a) In general, do nonmetals form anions or
cations?
Nonmetals generally form anions (-ve ions)
11. a) In general, do metals form anions or
cations?
Metals generally form cations (+ve ions)
11. c) Which nonmetal appears to be an
exception to these guidelines?
12. Name the family of elements that make 1anions.
11. c) Which nonmetal appears to be an
exception to these guidelines?
Hydrogen (not a surprise!)
12. Name the family of elements that make 1anions.
Halogens (Group 17, or 7A)
13. Name the family of elements that make 2+
cations.
14. For the main group elements is it
necessary to memorize the type of ions each
element makes or could you predict the ion
charge using a Periodic table?
13. Name the family of elements that make 2+
cations.
Alkaline earth metals (Group 2, or 2A).
14. For the main group elements is it
necessary to memorize the type of ions each
element makes or could you predict the ion
charge using a Periodic table?
14. For the main group elements is it
necessary to memorize the type of ions each
element makes or could you predict the ion
charge using a Periodic table?
We do not need to memorize types of ions
for main group elements - we can use their
group number to predict the charge - and all
members of the group will form the same
type of charge ion.
15. Where in the periodic table are the
elements found whose atoms make more than
one type of ion?
The transition elements - center of the
periodic table.
Remember writing this: The Octet Rule
Atoms tend to gain, lose or share electrons in
order to acquire a full set of eight valence
electrons.
Electron configurations like those of the Noble gases
with filled s and p orbitals of the same energy level are
unusually stable. (Note that Helium has only 2 valence
electrons, but that is because the 1st energy level can
only accommodate 2 electrons in its 1s orbital.)
Octet rule is useful for determining the type of ions that
elements are likely to form.
The Octet Rule in action
If atoms gain or lose electrons in order to acquire
a full set of eight valence electrons...
When a metal with one or two valence electrons reacts
with a nonmetal with 6 or 7 valence electrons we can
see that both can satisfy the octet rule by reacting with
each other so that 1 or 2 electrons are transferred from
the metal to the nonmetal. During this reaction process
metals cations (+ve ions) will form and at the same
time nonmetal anions (-ve ions) will form - and then the
oppositely charged ions will attract each other...
Ionic Bonding
The electrostatic force that holds oppositely charged
particles (cations and anions) together in an ionic
compound is referred to as an ionic bond.
Compounds that contain ionic bonds are referred to
as ionic compounds.
(When metals react with oxygen to form ionic
compounds those compounds are called oxides, most
other ionic compounds are called salts.)
Metals from
most of PT
What kind of chemical bonding will occur
between these 2 different types of
elements?
Any Group 1
(or group 2
metal, or any
transition
metal)
Na 11 p+
11 eNa•
Nonmetals
from top
right corner
Halogens
– make
easiest
examples
Cl 17 p+
17 e-
Metals from
most of PT
Any Group 1
(or group 2
metal, or any
transition
metal)
What kind of chemical bonding will occur
between these 2 different types of
elements? Family of compounds called
“Salts”
(see acids, bases and salts
later for details)
Na 11 p+
11 eNa•
Nonmetals
from top
right corner
Halogens
– make
easiest
examples
Cl 17 p+
17 e-
Metals from
most of PT
What kind of chemical bonding will occur
between these 2 different types of
elements?
Now (Na)
Na 11 p+
10 e= 1+
+
Na Sodium ion
Nonmetals
from top
right corner
Cl 17 p+
18 e= 1.
−
Cl
Chloride ion
- +
+ - +
+
+
-
-
Simplest
ratio of
ions is
1:1
NaCl
https://www.youtube.com/watch?v=d2geiGKFveE
(Why is what he does at the end not a good idea?)
Crystal Lattice
3D arrangement of
alternating positive and
negative ions in all directions
The electrostatic attraction
between oppositely charged
ions is ionic bonding
Binary Compounds
1. Hydrogen - Element exists as H2(gas)
LiH
BeH2
BH3
CH4
NH3
H2O
HF
NaH
MgH2 AlH3
SiH4
PH3
H2S
HCl
KH
CaH2
GaH3
GeH4
AsH3
H2Se
HBr
RbH
SrH2
InH3
SnH4
SbH3
H2Te
HI
CsH
BaH2
TlH3
PbH4
BiH3
H2Po
HAt
Group 1 elements exist as metallic solids
Li
Li2C2
Li3N
Li2O
LiF
Na
Li3P
Li2S
LiCl
K
Li3As
Li2Se LiBr
Rb
Li3Sb Li2Te
Cs
Li3Bi
LiI
Li2Po LiAt
Substitute Li with each of the others in the group
Group 2 elements exist as metallic solids
-
Be
-
BeC
Sr3N2 CaO
MgF2
-
Mg
-
-
Sr3P2 CaS
MgCl2
-
Ca
-
-
Sr3Ar2 CaSe MgBr2
-
Sr
-
-
Sr3Sb CaTe MgI2
2
-
Ba
-
-
Sr3Bi2 BaPo MgAt2
Group 13 elements exist as metallic solids after B
-
-
B
-
BN
B2O3
AlF3
-
-
Al
-
AlP
B2S3
AlCl3
-
-
Ga
-
GaAs B2Se3 AlBr3
-
-
In
-
SnSb B2Te3 GaI3
-
-
Tl
-
TlBi
B2Po3 GaAt3
Group 14 elements exist as solids (NM-Metalloid-M)
-
-
-
C
BN
CO2
CF4
-
-
-
Si
AlP
CS2
CCl4
-
-
-
Ge
GaAs CSe2
CBr4
-
-
-
Sn
SnSb CTe2
CI3
-
-
-
Pb
TlBi
CAt4
CPo2
Organic compounds of carbon
Grp 15 elements - NM - Metalloid- metal
Li3N
Be3N2 -
-
N2
NO,
N2O,
NO2
NF3
Na3N
Mg3N2 -
-
P
S4N4
-
K3N
Ca3N2 -
-
As
-
Rb3N
Sr3N2 -
-
Sb
-
Cs3N
Ba3N2 -
-
Bi
-
Group 17 Halogens (nonmetals)
LiF
BeF2
BF3
CF4
NF3
Cl2O
F2 (g)
NaF
MgF2
AlF3
SiF4
-
SF6
Cl2(g)
KF
CaF2
GaF3
GeF4
-
Br2(l)
RbF
SrF2
InF3
SnF4
-
I2(s)
CsF
BaF2
TlF3
PbF4
-
Naming Compounds Obviously we need a system (s)
Start with
Naming Ionic Compounds
(followed by Covalent compounds and
brief introduction to Organic compounds)
Naming Ionic Compounds
Part 1 Binary Compounds Pogil
Naming Ionic Compounds
What are the structural units that make up ionic
compounds and how are they named?
Why?
When working in Chemistry, it is often convenient
to write a chemical in symbols. For example we
might write down the substance table salt as
NaCl. In talking about chemistry, however, it is a
bit tacky to say “en-ay see-ell” when we want to
refer to a substance. Also in formal writing we
should use the name of the compound rather
than its symbols.
We need to learn how to say the proper
names of ionic substances.
Model 1 - Ion Charges for Selected Elements
1. a) Identify three elements that form only one
cation.
We need to learn how to say the proper
names of ionic substances.
Model 1 - Ion Charges for Selected Elements
1. a) Identify three elements that form only one
cation.
Hydrogen, Lithium, Beryllium etc. etc.
We need to learn how to say the proper
names of ionic substances.
Model 1 - Ion Charges for Selected Elements
1. b) Identify three elements that form only one
anion.
Nitrogen, oxygen, fluorine (any of the ones
shown).
We need to learn how to say the proper
names of ionic substances.
Model 1 - Ion Charges for Selected Elements
1. c) Identify three elements that form more then
one cation.
d) In what region of the periodic table are these
“multiple ion” elements usually located?
We need to learn how to say the proper
names of ionic substances.
Model 1 - Ion Charges for Selected Elements
1. c) Identify three elements that form more then
one cation. Iron, Nickel, Copper etc.
d) In what region of the periodic table are these
“multiple ion” elements usually located?
The transition elements and low in group 14 (4A)
2.
+
Consider K and S
2-
Write chemical formulas for all possible ionic
compounds involving these ions, using the
simplest ratio(s) of potassium(K) to sulfur(S).
Keep in mind that the sum of the charges in
an ionic compound must equal zero.
1+ (-2) = -1
how make it 0?
2.
+
Consider K and S
2-
Write chemical formulas for all possible ionic
compounds involving these ions, using the
simplest ratio(s) of potassium(K) to sulfur(S).
Keep in mind that the sum of the charges in
an ionic compound must equal zero.
1+ (-2) = -1
2(1+) - 2 = 0
how make it 0?
Need 2 K+ to every 1 S2-
2.
+
Consider K and S
2-
K2S
We use the charges on the ions to figure out
what the formula will be, but we don’t show
that information when we write a formula.
Only this one ratio makes an electrically
neutral compound.
2.
Consider Fe
For 2+ ion
2+ - 2 = 0
1:1 Ratio
Formula: FeS
2+
3+
or Fe and S
2+ (-2) = 0
2-
2.
Consider Fe
For 2+ ion
2+
3+
or Fe and S
2-
For 3+ ion
2+ (-2) = 0
3+ - 2 = +1
1:1 Ratio
Common multiples?
Formula: FeS
2.
Consider Fe
2+
3+
or Fe and S
2-
For 2+ ion
For 3+ ion
2+ (-2) = 0
3+ - 2 = +1
1:1 Ratio
lowest common multiple?
2(3+) + 3(-2) = 0
Formula: FeS
2.
Consider Fe
2+
3+
or Fe and S
For 2+ ion
For 3+ ion
2+ (-2) = 0
3+ - 2 = +1
1:1 Ratio
LCM?
2(3+) + 3(-2) = 0
Ratio Fe:S is 2:3
Formula: FeS
2-
2.
Consider Fe
2+
3+
or Fe and S
For 2+ ion
For 3+ ion
2+ (-2) = 0
3+ - 2 = +1
1:1 Ratio
LCM?
2(3+) + 3(-2) = 0
Ratio Fe:S is 2:3
Formula: FeS
Fe2S3
2-
Model 2 - Ionic Compound Names
(Metals that form one ion ONLY)
4. Circle the symbol for the metal in each.
NaCl
Sodium chloride
Zn3P2 Zinc phosphide
CaS
Calcium sulfide
Al2O3 Aluminum oxide
AgS
Silver sulfide
SrCl3 Strontium chloride
5. The symbol of the metal comes first in
the formula, and the name comes first in
the name.
5.
NaCl
Sodium chloride
Zn3P2 Zinc phosphide
CaS
Calcium sulfide
Al2O3 Aluminum oxide
AgS
Silver sulfide
SrCl3 Strontium chloride
6. a) Zinc can only form a 2+ ion
b) Phosphide is a 3- ion.
6.
NaCl
Sodium chloride
Zn3P2 Zinc phosphide
CaS
Calcium sulfide
Al2O3 Aluminum oxide
AgS
Silver sulfide
SrCl3 Strontium chloride
7. Explain why a 3 to 2 ratio of ions is
necessary for the compound zinc
phosphide.
The sum of the charges on all the ions in the
compound has to equal zero.
2+ (-3) = -1
Not zero
7. Explain why a 3 to 2 ratio of ions is
necessary for the compound zinc
phosphide.
The sum of the charges on all the ions in the
compound has to equal zero.
2+ (-3) = -1
Not zero, look for LCM
7. Explain why a 3 to 2 ratio of ions is
necessary for the compound zinc
phosphide.
The sum of the charges on all the ions in the
compound has to equal zero.
2+ (-3) = -1
Not zero, look for LCM
3(2+) + 2(-3) = 6+ (-6) = 0
7. Explain why a 3 to 2 ratio of ions is
necessary for the compound zinc
phosphide.
The sum of the charges on all the ions in the
compound has to equal zero.
2+ (-3) = -1
Not zero, look for LCM
3(2+) + 2(-3) = 6+ (-6) = 0
So ratio Zn: P has to be 3:2 Formula: Zn3P2
8. The compound carbon dioxide has a
name that gives you a hint as to how
many oxygen atoms are in the
compound.
Is there anything in the name zinc phosphide
that indicates there are three zinc and two
phosphorus ions in the formula unit?
No.
9. Is there any other ratio of zinc and
phosphorus ions that could exist?
Explain your answer.
No other ratios of zinc (2+) and phosphide (3-)
ions are possible. Any other ratio of ions would
result in a substance with a net charge, which
would not satisfy the requirement that
compounds have no net charge.
10. Explain why you don’t need to specify
the number of ions in the compound
when you are naming ionic substances.
If the charges on the ions are known, then there
will only be one proper ratio between them in
the compound, so we do not need to include
any more additional information in the name for
the compound.
11. Model 2 is labelled “ Metals that form
one ion.” What other metals that also
form one ion could be included in the
Model 2 list?
H+, Li+, K+, Rb+
Be2+, Mg2+, Sr2+, Ba2+,
Al3+
12. Describe how the names of the
nonmetal elements in Model 2 are
changed when they are in their anion
forms.
12. Describe how the names of the
nonmetal elements in Model 2 are
changed when they are in their anion
forms.
The end of the element name is changed to
“ide” to indicate anion form.
13. Name the following ionic compounds
using what we learned in Model 2.
Li2O
MgF2
Al2S3
K3N
13. Name the following ionic compounds
using what we learned in Model 2.
Li2O
MgF2
Al2S3
K3N
Lithium oxide
13. Name the following ionic compounds
using what we learned in Model 2.
Li2O
Lithium oxide
MgF2
Magnesium fluoride
Al2S3
K3N
13. Name the following ionic compounds
using what we learned in Model 2.
Li2O
Lithium oxide
MgF2
Magnesium fluoride
Al2S3
Aluminum sulfide
K3N
13. Name the following ionic compounds
using what we learned in Model 2.
Li2O
Lithium oxide
MgF2
Magnesium fluoride
Al2S3
Aluminum sulfide
K3N
Potassium nitride
14. Provide the chemical formula for each
of the following ionic compounds.
Barium chloride
Ba2+ Cl2+ -1 = +1 not zero’
2+ 2(-1) = 0 1:2 ratio
Formula is : BaCl2
Barium chloride
14. Provide the chemical formula for each
of the following ionic compounds.
Magnesium oxide
Mg2+ O22+ -2 = 0
1:1 ratio, easy
Formula is :
14. Provide the chemical formula for each
of the following ionic compounds.
Magnesium oxide
Mg2+ O22+ -2 = 0
1:1 ratio, easy
Formula is : MgO
Magnesium oxide
15. Consider the 2 chemical formulas you
wrote in question 4 for compounds of iron
and sulfur. Would the name “iron sulfide”
be sufficient to uniquely identify either of
those compounds?
The name “iron sulfide” could refer to either FeS or
Fe2S3
which means the name would be
ambiguous, so this name would not be sufficient to
uniquely identify the compounds.
Naming ionic compounds when the metal
can form more than one positive ion...
… to be continued.
Have a wonderful Thanksgiving Break.
God Bless you all and your families.