Academic Chemistry

Unit 6: Properties of Ionic Compounds

Textbook Readings and Homework:

6 – 3 Ionic Bonding and Ionic Compounds Page 180 #1-3

7-1 Chemical Names and Formulas p203-210 Page 215 #1, 2abc, 3abcd

EOC’s - page 195 # 1, 19a, 37a-d, 38 page 235 # 4,6,7,8,15

Vocabulary:

Octet Rule Ionic Bond Lewis Dot Structure Nomenclature

Valence Electrons Covalent Bond Formula Unit Electronegativity

Monatomic Ion Non-polar Covalent Bond Ductility Anion

Polyatomic Ion Polar Covalent Bond Malleability Cation

Objectives:

1.  Give the names and formulas of cations, anions, and ionic compounds.

2.  Write chemical formulas for ionic compounds using common ion list and “criss-cross” method

3.  Determine the number of valence electrons an atom has based on its position on the periodic table.

4.  Draw Lewis Dot structures to show the arrangement of valence electrons in atoms

5.  Determine the charge an ion with likely form based on the position of the element on the periodic table and using the octet rule.

6.  Explain why the properties of an ion are different from those of the neutral atom.

7.  Describe the process of forming an ionic bond (be able to draw a picture illustrating the formation of an ionic bond)

Activities and Labs

1.  Cut and Paste Ionic Compound Cards

2.  Go Fish for an Ion

3.  Lab: Forming Ionic Compounds (Well Plates and Ions in Dropper Bottles)

4.  Lab: Ionic vs Covalent Compounds (Testing for Properties such as Melting Point/Conductivity)

5.  Lab: Formula of an Ionic Compound


Complete each statement below by writing the correct term or phrase.

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  1. An anion is an ion with a charge.
  1. electrons occupy the outermost energy level of an atom.

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  1. The chloride ion and the chlorine atom have electron configurations.

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  1. A cation is an ion with a charge.

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  1. Many stable ions have an electron configuration of a

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Answer the following questions in the space provided.

  1. How do the outer-shell electron configurations for ions of Group 1, Group 2, and Group 15, Group 16, and Group 17 elements compare with those of the noble gases?
  2. How many valance electrons do atoms in Group 1, Group 2, Group 15, Group 16, and Group 17 have?

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  1. State the octet rule.

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  1. Ions of calcium, fluorine magnesium, and iodine have electron configurations

that are similar to which noble gases?

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  1. Explain why the properties of ions differ from those of their parent atoms.

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  1. Why do atoms of metals form cations?

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  1. Why do atoms of nonmetals form anions?

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Electron Transfer Diagrams

Ionic bonding occurs when a metal transfers one or more electrons to a nonmetal in an effort to attain a stable octet of electron. For example, the transfer of an electron from sodium to chlorine can be shown by a Lewis dot diagram

Na . + Cl Na+ Cl-

1 : 1

NaCl

Calcium would need two chlorine atoms to get rid of its two valance electrons

Cl + Ca + Cl Ca+2 Cl-

1 : 2

CaCl2

Show the transfer of electrons in the following combinations

1.  K + F
2.  Mg + I
3.  Be + S
4.  Na + O
5.  Al + Br
Elements / Lewis Dot Notation / Electron Transfer / Ionic Form of atoms / Ratio of atoms / Chemical Formula
Ba and F / Ba F
K and S / K and S
Al and S / Al and S
Li and N / Li and N
Ca and S / Ca and S
Al and N / Al and N
Ca and O / Ca and O
Li and P / Li and P
Ba and O / Ba and O
Ca and P / Ca and P


The Crisscross Method

A binary compound is one made of two different elements. There can be one of each element such as in sodium bromide or potassium iodide. There can also be several of each element such as lithium oxide or aluminum bromide.

Please remember that all elements involved in this lesson have ONLY ONE charge. That includes BOTH the metal AND the nonmetal involved in the formula.

Points to remember about writing the formula from the name

  1. The order in a formula is first the cation, then the anion.
  2. You must know the charges associated with each cation and anion.
  3. The sum of the positive charge and the sum of the negative charges MUST add up to zero.
  4. You MAY NOT adjust the charges of the cations or anions to get a total charge of zero.
  5. You MAY adjust the subscripts to get a total charge of zero.

Write down the Mg2+ and Cl¯ right next to each other

Move the positive charge (dropping the sign) to the subscript position of the anion:

Mg2+ Cl-1

Move the negative charge (dropping the sign) to the subscript position of the cation:

Mg Cl-12

The result of all this moving is: Mg1Cl2
Since subscripts of one are not written, but understood to be present, the final answer is: MgCl2

Or Least Common Multiple Technique

The rules to follow are:

·  the total positive charges must equal the total negative charges.

·  you cannot change the charges given to you.

·  adjust the subscripts to equalize the charges.

Problem: write the formula for aluminum sulfide.

  1. Write Al3+ and S2¯ right next to each other.
  2. Select the least common multiple between the two charges (ignoring the signs). In this case it is 6. This is the amount of positive charge and negative charge you need for a correct formula.
  3. In other words, you need sufficient aluminum atoms to make a +6 charge and you need sufficient sulfur atoms to make a -6 charge.
  4. Obviously (I hope), you see you need two Al and three S, so the correct formula is Al2S3.

Problem: write the formula for radium oxide.

  1. Write Ra2+ and O2¯ right next to each other.
  2. The least common multiple between the two charges is 2.
  3. This means that +2 is the total positive charge and -2 is the total negative charge needed.
  4. One Ra and one O each provide the needed amount of charge, so the correct formula is RaO.

Ionic Formulas and Naming

The Rules: Compounds must be NEUTRAL: Have as much positive charge as negative Charge. A Subscript in a formula tells how many of the atom just before it there are: H2O = The subscript 2 means there are 2 H’s. This is needed to get 2+ charges (H is +1) to balance the –2 charge of the O.

Names:

Cation (+ ions) use their element name. If it is a transition metal, the name is followed by the charge on the ion in parenthesis in Roman Numerals: Ca2+ = Calcium ion, Fe2+ = Iron (II) ion.

Anions (- ions) change the elements name to end in ide. O2- = Oxide. N3- = nitride, Cl- chloride.

A compound is named by the name of the cation followed by the name of the anion. FeCl2 = iron (II) chloride

Cation / Charge / Name / Anion / Charge / Name / Compound Formula / Compound Name
Na / Cl
Ca / Br
K / O
Mg / S
Sr / Cl
Al / F
Cs / Te
Li / N
Be / P
Ga / Se
Fe / 3+ / I
Fe / 2+ / C
Cu / 2+ / As
Mn / 4+ / O
V / 5+ / S

Use the Criss-Cross method to write the formula of each compound

Ions
/ Chloride
Cl1- / Hydroxide
OH1- / Nitrate
NO31- / Sulfate
SO42- /

Sulfide

S2- /

Carbonate

CO32- / Phosphate
PO43-

Sodium

Na1+
Ammonium
NH41+ /

Calcium

Ca2+

Aluminum

Al3+
Iron (II)
Fe2+
Iron (III)
Fe3+
Gold (I)
Au+
Gold (III)
Au+3
Copper (I)
Cu1+
Copper (II)
Cu2+

Nomenclature Ionic Compounds

Write the formula for the binary ionic compound formed between each of the following pairs of elements

1.  magnesium and iodine ______

2.  potassium and sulfur ______

3.  aluminum and chlorine ______

4.  zinc (II) and bromine ______

5.  cesium and sulfur ______

6.  strontium and oxygen ______

7.  calcium and nitrogen ______

Name the following binary ionic compounds

8.  BaF2 ______

9.  CaO ______

10.  AgF ______

11.  CdO ______

12.  K3N ______

13.  NaI ______

14.  AlBr3 ______

Write the formula and give the name using the criss cross for the compound formed between each of the following pairs of ions

15.  Cu+1 and O-2 ______

16.  Fe+3 and S-2 ______

17.  Cu+2 and Cl-1 ______

18.  Sn+2 and Cl-1 ______

19.  Hg+2 and O-2 ______

20.  Sn+4 and S-2 ______

21.  V+2 and F-1 ______

Write formulas for the following ionic compounds involving polyatomic ions

22.  copper(II) nitrate ______

23.  potassium chlorate ______

24.  sodium hydroxide ______

25.  ammonium acetate ______

26.  calcium carbonate ______

27.  potassium permanganate ______

28.  sodium sulfate ______

29.  iron (III) nitrate ______

Give the names of the following compounds involving polyatomic ions

30.  Ag2SO4 ______

31.  NaMnO4 ______

32.  Ba(OH)2 ______

33.  NH4NO3 ______

34.  Fe(ClO)2 ______

35.  Ca(NO3)2 ______

36.  K2SO3 ______

37.  NaCH3COO ______


Writing Formulas From Names

Write the formulas of the following compounds

Ammonium phosphate

Iron (II) oxide

Iron (III) oxide

Ammonium Hydroxide

Calcium chloride

Potassium nitrate

Aluminum sulfate

Copper (II) sulfate

Lead (IV) chromate

Sodium hydrogen carbonate

Zinc (II) nitrate

Aluminum sulfite
Ionic Bonding and Salts

  1. The arrangement of ion in sodium chloride shows that each ion is surrounded by

oppositely-charged ions.

  1. The attractive force between sodium ions and chloride ions results in an arrangement of ions in repeating units arranged to form a
  1. In the sodium chloride crystal arrangement, the net effect is that the between oppositely charged ions is significantly greater than between ions of like charge.
  1. The arrangement of cations and anions depends on the and

the of the ions.

Answer the following questions in the space provided.(These look like great test questions)

  1. Briefly describe why the structure of ionic compounds causes the compounds to be hard. ______
  1. How is an ionic bond formed? ______
  1. What is a salt. ______
  1. Why do ionic compounds have high melting points and high boiling points?
  1. Why are ionic solids generally poor conductors of electricity? ______

______

  1. When are salts excellent conductors of electricity? ______

______

  1. Name five characteristics of ionic compounds, and how the electron transfer causes these properties ______
  1. Describe the structure of salt crystals, draw a diagram showing why ionic compounds are brittle

______


Chemical Formulas and Names

Find the Correct name based on the formulas listed below.

A / C / E / T / A / H / P / S / O / H / P / M / U / I / S / S / A / T / O / P / D
S / E / T / A / H / P / S / O / H / P / R / E / V / L / I / S / E / S / F / G / A
I / E / D / I / X / O / R / D / Y / H / N / O / R / I / J / L / M / O / N / P / R
L / A / L / E / A / D / P / H / O / S / P / H / A / T / E / T / A / D / V / X / E
V / M / Z / A / C / E / G / I / K / M / O / I / Q / H / Z / S / G / I / U / W / T
E / M / Y / C / O / P / P / E / R / B / R / O / M / I / D / E / N / U / E / B / A
R / O / D / F / H / T / L / N / P / O / R / T / N / U / V / X / E / M / D / Z / H
H / N / A / C / F / G / I / K / N / M / O / C / Q / M / W / U / S / H / I / W / P
Y / I / Y / B / D / F / H / C / J / L / P / N / P / O / R / T / I / Y / R / V / S
D / U / X / Z / A / E / H / C / G / H / I / K / M / X / O / Q / U / D / O / S / O
R / M / U / W / Y / L / B / D / O / F / H / J / L / I / N / P / M / R / L / R / H
O / O / T / U / O / W / Y / S / A / E / C / G / I / D / K / M / H / O / H / O / P
X / X / Q / R / S / U / P / W / Y / B / D / F / H / E / T / L / Y / X / C / N / M
I / I / I / P / R / H / T / V / X / Z / A / E / C / G / I / K / D / I / N / M / U
D / D / P / R / A / L / U / M / I / N / U / M / B / R / O / M / I / D / E / T / I
E / E / V / T / X / E / T / A / R / T / I / N / C / N / I / Z / D / E / G / Z / R
B / D / E / F / H / J / Z / I / N / C / N / I / T / R / A / T / E / L / O / N / A
P / R / T / V / Z / B / D / F / E / T / A / R / T / I / N / M / U / I / R / A / B
H / J / L / N / P / C / A / L / C / I / U / M / F / L / U / O / R / I / D / E / A
E / T / A / N / O / B / R / A / C / M / U / I / S / S / A / T / O / P / Y / Z / F
R / T / V / X / E / D / I / M / O / R / B / N / E / G / O / R / D / Y / H / N / U

Ag3PO4 Fe(OH)2 NaOH

AlBr3 HBr (NH4)2O

Ba(NO2)2 HCl Pb3(PO4)2

Ba(PO4)2 K2CO3 Zn(NO3)2

CaF2 K3PO4 Zn3(PO4)2

CuBr2 Li2O AgOH

FeCl3 MgH2

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