SCIENCE 10
CHAPTER 2:
Naming, formulas, &
properties
NAME:______________________
DAY: _____ BLOCK: _____
W. P. Wagner 1
Understanding Matter – WHMIS symbols
Ionic Compounds Students will:
Explain, using the periodic table, how elements combine to form compounds, and follow IUPAC guidelines for naming ionic compounds and simple molecular compounds
predict formulas and write names for ionic compounds using a periodic table, a table of ions and IUPAC rules
Made up of positive ions (cations )METALS and negative ions (anions) NON-METALS
Always have no net charge (i.e. are neutral) therefore, the ratio of cations to anions must be such that the total positive charge and total negative charge are equal (lowest whole number ratio)
e.g.
Always named according to the following format:
Types of ions and ionic compounds:
W. P. Wagner 2
METAL (+) NON (-)ide
MAIN GROUP ANIONS
MAIN GROUP CATIONS MONATOMIC
IONS
TRANSITION METAL CATIONS
POLYATOMIC ANIONS
POLYATOMIC CATIONS POLYATOMIC
IONS IONS
BINARY IONIC
COMPOUNDS TERNARY IONIC
COMPOUNDS HYDRATES
I O N I C C O M P O U N D S
I BINARY IONIC COMPOUNDS: (Compounds composed of a metal and a non-metal) Rules for naming:
1. Name the metallic ion first, followed by the non-metallic ion.
(the non-metallic ion ends in "ide")
2. Ionic compounds always start with a metal or an ammonium ion.
Name the following ionic compounds:
Ag
2S __________________ AlCl3 _________________
KCl ____________________ K
2O _
__________________
CaS ____________________ Al2O3____
__
____________
CaF2________
____________ AgCl ___________________
Mg3N2 ________
__
________ Li2S __________
_________
K2S ___________
_________ BaI2______________
______
RbF _____________________ LiBr____________________
Na2O_____________
_______ AlBr3______________
_____
BaO _____________________ MgS__ _________________
Sr3N2____________
__
_____ GaCl3______________
_____
Ag3P_____________
_______ ScN____ _________________
CdS_____________________ InP______________________
BaI2______________
______ BeS_____________________
Al2S3____________
__
_____ MgSe__________________
GeCl4______________
_____ Cs3N_____________
_______
W. P. Wagner 3
Ionic compounds
- Formed when metals ions bind to non-metal ions; called an ___________________.
- Called salts (just like table salt). When the positive and negative charges attract each other a _____________ _____________ structure is formed.
o Each crystal could contain thousands, millions or trillions of ions;
the number varies from crystal to crystal.
.
.
- Formulas for ionic compounds tell you the _____________ of metal ions to non-metal ions.
o It is impractical to use a chemical formula showing the exact number of ions since the exact number varies from crystal to crystal. Instead we create a RATIO using subscript numbers
o For example the formula NaCl tells us that, for every sodium ion, there is one chloride ion. MgCl
2tells us that, for every magnesium ion, there are two chloride ions.
- To tell what the ratio is we rely on the knowledge that ionic compounds are formed from ions.
o Since chloride ions have a charge of one negative, and calcium ions have a charge of positive two, it takes two chloride ions to cancel the charge of one calcium ion.
o Since the aluminum ion has a charge of positive three, and the oxide ion has a charge of positive two the ratio of aluminium ions to oxide ions 2:3
Name Summary of Charge Formula
magnesium chloride MgCl
2sodium bromide
NaF silver sulfide
K
2O cesium oxide
Al
2S
3calcium phosphide
ZnCl
2W. P. Wagner 4
Complete the following table by either writing the correct chemical formula or IUPAC name.
Chemical
Formula Summary of Charge Name of Compound
eg. CaCl 2 Ca 2+ , Cl - , Cl - calcium chloride
1. potassium iodide
2. MgO
3. aluminum chloride
4. NaBr
5. CaO
6. lithium nitride
7. Al 2 O 3
8. barium chloride
9. sodium chloride
10. ZnO
11. silver bromide
12. magnesium hydride
13. magnesium chloride
14. zinc chloride
15. Ag 2 S
16. potassium chloride
17. CaF 2
18. sodium sulphide
19. CaH 2
20. zinc sulphide
W. P. Wagner 5
Writing formulas for Ionic Compounds
1. When given the name, write the symbol and charge for each ion.
2. Remember all compounds are electrically neutral.
3. Use subscripts to equalize the total number of positive and negative charges.
(The formula shows the lowest ratio of positive to negative ions.)
1Example:
Aluminum oxide Al3+ O2- (3+)2 = 6+ (2-)3 = 6- Al2O3 Write formulas for the following:
l. aluminum oxide_________________ 14. barium chloride _______________
2. silver fluoride _________________ 15. scandium nitride ______________
3. potassium sulfide ______________ 16. gallium selenide ______________
4. calcium nitride ________________ 17. beryllium arsenide ____________
5. sodium phosphide_______________ 18. zinc sulfide __________________
6. aluminum fluoride ______________ 19. calcium iodide ________________
7. magnesium oxide _______________ 20. lithium bromide _______________
8. cesium nitride_________________ 21. sodium fluoride _______________
9. calcium hydride ________________ 22. strontium phosphide ___________
10. silver oxide __________________ 23. sodium sulfide ________________
11. calcium phosphide_____________ 24. gallium oxide_________________
12. zinc bromide__________________ 25. indium fluoride_______________
13. francium nitride_______________ 26. magnesium fluoride____________
1
W. P. Wagner 6
Composition of Chemical Compounds - The Stock System
The Stock System. Some ions can exist with different ion charges in different situations. For example, iron can exist as Fe
3+and Fe
2+. To distinguish one from the other, Roman numerals are used in the name of compounds that are made with ions that can have different charges.
Fe
3+is called the iron (III) ion and
Fe
2+is called the iron (II) ion.
Write the chemical formula for iron (II) oxide. ________, for iron (III) oxide. ________
Complete the following table using the Stock System for naming ionic compounds. Remember that all transition metals except for aluminum, zinc and silver require the Roman numeral to specify ion charge.
Chemical Formula
IUPAC Name Summary of Charges 1. Cu 3 N 2 copper (II) nitride Cu 2+ , Cu 2+ , Cu 2+ , N 3- , N 3-
2. gold (I) chloride
3. Al 2 S 3
4. tin (II) oxide
5. antimony (V) bromide
6. SbF 3
7. CuCl
8. Fe 2 Se 3
9. ZnCl 2
10. aluminum sulphide
11. mercury (I) nitride
12. AlP
13. Ni 2 S 3
14. VI 5
15. cobalt (II) phosphide
16. chromium (II) hydride
17. silver telluride
W. P. Wagner 7
Composition of Chemical Compounds - Ternary Ionic Compounds
Ternary ionic compounds are usually compounds made from polyatomic ions. These polyatomic ions are identified on your periodic table in the box at the top of the page. Generally, if you don't recognize the name of a substance it is a polyatomic ion.
For example: If asked to write the formula for sodium sulphate. You can recognize the sodium part but sulphate may be a word you don't recognize. In that case check the box containing the
polyatomic ions. Sulphate shows up as SO
42-. This means it is a polyatomic ion with a charge of -2.
To write the formula for the compound sodium sulphate, you need two sodium ions and one sulphate ion. Na
++ Na
++ SO
42-makes Na
2SO
4and it has a neutral charge so you are done.
Whenever you need multiple polyatomic ions, you must put parentheses around the polyatomic ion and add the subscript outside the parentheses.
E.g. Write the name of Mg(ClO)
2____________________________________.
The following table that requires you to name some common polyatomic ions. Remember that complex ions are not molecules and cannot exist by themselves as they are on the periodic table or in this exercise.
Ion Name Formula Ion Name Formula
1. silicate 6. sulfite
2. ClO 3 - 7. NO 3 -
3. NH 4 + 8. hydrogen sulfide
4. dichromate 9. HPO 4 2-
5. OH - 10. CH 3 COO -
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Naming Compounds with Polyatomic Ions
Use the table of polyatomic ions to complete the following exercise. Only those polyatomic ions listed on the periodic table are used in science 10.
International Formula Summary of Charges IUPAC English Name 1. Na 2 CO 3
2. (NH 4 ) 2 CO 3
3. FeSO 4
4. lithium hydroxide
5. aluminum hydroxide
6. NaClO
7. potassium dichromate
8. LiC 6 H 5 COO 9. NaNO 2
10. ammonium sulphate
11. sodium hydrogen carbonate
12. Na 3 PO 4
13. calcium dihydrogen
phosphate 14. PbCrO 4
15. sodium hydrogen sulphate
16. KMnO 4
17. aluminum silicate
18. Li 2 CO 3
19. potassium cyanide
Naming Compounds with Polyatomic Ions and the Stock System
Complete the following table using the stock system and polyatomic ions for naming compounds.
Chemical
Formula Summary of Charge Name of Compound eg. Cu
2SO
3Cu
+, Cu
+, SO
32-copper(I) sulphite
1. uranium(IV) oxide
2. lead(IV) sulphate
3. Sn(HPO
4)
24. Al
2O
35. manganese(IV) iodate
6. Sb
2S
37. thallium(III) hydroxide
8. HgS 9. MoS
310. polonium (II) thiosulphate
11. FeSO
412. lead(IV) chlorate
13. Hg(NO
3)
214. ZnSe 15. V
2O
516. tin (II) borate
17. chromium (III) phosphate
18. TiO
219. Ag
2SO
320. AuCl
321. uranium(IV) cyanide
22. NiBr
223. cobalt(II) hypochlorite
Composition of Chemical Compounds - Hydrated Compounds
Hydrated compounds are compounds that contain water as part of their structure. Some compounds are water seeking and are most stable when they are attached to many water molecules.
To name these substances we need to know the common prefixes so that the compounds can be described correctly.
The common substance, Epsom salts, is named magnesium sulphate heptahydrate and its formula is MgSO
47H
2O. If you remove the water by heating or by some other means, the compound can be used to soak up water as it gets back the water you have taken away. Anti-perspirants are made in this way.
Generally the chemical formula ends with __H
2O
- where the blank is the correct value for the number of water molecules that are bonded to the ionic compound.
The IUPAC name can be written in two different ways. For the above example MgSO
47H
2O would be written either;
- using the prefix system as magnesium sulphate heptahydrate or - using the number system as magnesium sulphate-7-water.
***You must be able to read and write the names of hydrated compounds using either system.
Eg. – Cu(NO
3)
2 4 H
2O
tetrahydrate
copper (II) nitrate
Full Name: copper (II) nitrate tetrahydrate
1 - mono 2 - di 3 - tri 4 - tetra 5 - penta
6 - hexa
7 - hepta
8 - octa
9 - nona
10- deca
Naming Hydrated Compounds. Complete the following table.
Name of Hydrate Common Name, Use or Discrition Formula
e.g. copper(II) sulphate pentahydrate
blue vitriol, bluestone, copper
plating, blue solid CuSO 4 5H 2 O (s)
1. Epsom salts, white solid explosives,
matches MgSO
47H
2O
(s)2. sodium carbonate decahydrate
washing soda, soda ash, water softener, white solid
3. white solid, fireproofing wood,
disinfectants, parchment paper MgCl
26H
2O
(s)4. barium chloride dihydrate
white solid, pigments, dyeing fabrics, tanning leather
5. white solid, photographic emulsions Cd(NO
3)
24H
2O
(s)6. white solid, embalming material,
fireproofing lumber, vulcanizing ZnCl
25H
2O
(s)7. zinc sulphate heptahydrate
white solid, clarifying glue, preserving wood and skins
8. lithium chloride tetrahydrate
white solid, soldering aluminum in fireworks
9. photographic hypo, antichlor, white solid Na
2S
2O
35H
2O
(s)10 cobalt(II) chloride hexahydrate
pink solid, humidity and water indicator, foam stabilizer in beer
11 white solid, antiperspirant AlCl
36H
2O
(s)12 de-icer used on icy highways, added to
cement mixtures to prevent freezing CaCl
22H
2O
(s)13 barium hydroxide octahydrate
white solid, manufacture of glass, water softener
14 nickel(II) chloride hexahydrate
green solid, manufacture of glass, water softener
15 Glauber's salt (a medicine), white solid,
drying agent Na
2SO
410H
2O
(s)Composition of Chemical Compounds - Solubility of Ionic Compounds
Students will:
predict whether an ionic compound is relatively soluble in water, using a solubility chart Ionic compounds are determined to have either high solubility or low solubility when placed into water. Since it is not possible for you to know which is which, a solubility chart is provided for you on the periodic table. The top row of ions on the Solubility Chart contains the high solubility (H)
compounds; the bottom row contains the low solubility (L) compounds.
To determine the solubility of an ionic compound you first look for the anion on the chart (the non- metal ion). Once you find the anion, there are two choices for the cation in the compound. If it appears in the top box below the anion name, it has high solubility and is therefore said to be aqueous
(aq)