2. Working backwards: name to formula
• It’s possible to determine a formula from a name
• E.g. What is the formula of sodium oxide?
• To get the answer, first write the valences:
Na1
O2
→ Na2O
• What is the formula of copper(II) oxide?
Cu2
O2
→ Cu2O2 → CuO
• For covalent compounds, simply use the
prefixes to tell you the number of each element:
• What is the formula for dinitrogen trioxide?
N2O3
• Give formulae for: lithium sulfide, dinitrogen
monoxide, lead(IV) sulfate
3. Write and name the following
covalent compounds (IUPAC)
Li1
S2
→ Li2S
N2O
4 2
lithium sulfide
dinitrogen monoxide
lead(IV) sulfate
4. 1. Name each according to IUPAC rules:
a) ZnS, b) FeCl3, c) CaCO3, d) P2O5, e) NaCN,
f) N2F2, g) MgHPO4, h) Cu(BrO3)2, i) K2O, j) BF3
1. Give the valence of a) Fe in FeO, b) Mn in MnO2
3. Write formulas for: a) sodium oxide,
b) potassium iodide, c) lead(IV) sulfide,
d) mercury(I) oxide, e) Iron(II) oxide,
f) iron(II) phosphate, g) copper(II) fluoride,
h) dichlorine monoxide, i) silver
sulfide, j) magnesium nitride, k)
aluminum hypochlorite, l) iodine
Assignment
5. Complete exercises on handout
Steps:
1. Determine if its ionic or covalent
2. If ionic, determine if its metal has one
or more valence
3. Name according to appropriate rules
6. Answers – 1, 2
a) zinc sulfide
b) iron(III) chloride
c) calcium carbonate
d) diphosporus pentoxide
e) sodium cyanide
f) dinitrogen difluoride
g) magnesium hydrogen phosphate
h) copper(II) bromate
i) potassium oxide
j) boron trifluoride
2 a) 2 b) 4
7. Answers – 3
a) Na2
O
b) KI
c) PbS2
d) Hg2
O
e) FeO
f) Fe3
(PO4)2
g) CuF2
h) Cl2O
i) Ag2
S
j) Mg3
N2
k) Al(ClO)3
l) IF5
m) CaCrO4
n) P2
S5
8. • Bases contain an OH group
• C6H12O6 does not have an OH group
• If an OH group is present it will be clearly
indicated: e.g. NaOH, Ca(OH)2
• Also notice that bases have a metal (or positive
ion such as NH4
+
at their beginning)
• Bases are named like other ionic compounds:
• +ve is named first, followed by the polyatomic
ion
Naming Bases
- calcium hydroxide
- copper(I) hydroxide
- Al(OH)3
- NH4OH
Ca(OH)2
CuOH
aluminum hydroxide
ammonium hydroxide
9. • All acids start with H (e.g. HCl, H2SO4)
• 2 acids types exist: binary acids and oxyacids
Binary: H + non-metal. E.g. HCl
Oxy: H + polyatomic ion. E.g. H2SO4
• Each have different naming rules.
Binary acids: naming depends on state of acid
• If it’s not aqueous: hydrogen + non-metal
HCl(g) = hydrogen chloride
• If it is aqueous: hydro + non-metal + ic acid
HCl(aq) = hydrochloric acid (aqueous hydrogen chloride)
Naming Acids: Binary acids
HBr(s) HI(aq)
H2S(aq) H2S(g)
hydrogen bromide hydr(o)iodic acid
hydrogen sulfidehydrosulfuric acid
10. • Naming does not depend on the state (aq)
• 1) name the polyatomic ion
2) replace ate with ic, ite with ous
3) change non-metal root for pronunciation
4) add “acid” to the name
E.g. H2SO3
Naming Acids: Oxyacids
HNO2 hypochlorous acid
H3PO4(aq) carbonic acid
1) sulphite, 2) sulphous,
3) sulphurous, 4) sulphurous acid
11. • Naming does not depend on the state (aq)
• 1) name the polyatomic ion
2) replace ate with ic, ite with ous
3) change non-metal root for pronunciation
4) add “acid” to the name
E.g. H2SO3
Naming Acids: Oxyacids
HNO2 hypochlorous acid
H3PO4(aq) carbonic acid
1) sulphite, 2) sulphous,
3) sulphurous, 4) sulphurous acid
- nitrous acid - HClO
- phosphoric acid - H2CO3
12. a) chloric acid
b) hydrosulfuric acid
c) hydrobromic acid
d) phosphorous acid
e) iodic acid
f) HCl(g)
g) HCl(aq)
h) H2SO4(s)
i) H2SO4(aq)
j) HClO2
k) HF(aq)
Assignment: give formula or name
a) HClO3
b) H2S(aq)
c) HBr(aq)
d) H3PO3
e) HIO3
f) hydrogen chloride
g) hydrochloric acid
h) hydrogen sulphate
i) sulfuric acid
j) chlorous acid
k) hydrofluoric acid
13. • Some compounds contain H2O in their struc-
ture. These compounds are called hydrates.
• This is different from (aq) because the H2O is
part of the molecule (not just surrounding it).
• The H2O can usually be removed if heated.
• A dot separates water: e.g. CuSO4•5H2O is
copper(II) sulfate pentahydrate.
• A greek prefix indicates the # of H2O groups.
Hydrates
sodium sulfate decahydrate
nickel(II) sulfate hexahydrate
Na2CO3•H2O
BaCl2•2H2O
Na2SO4•10H2O
NiSO4•6H2O
sodium carbonate monohydrate
barium chloride dihydrate
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