Chapter 7 Study Guide ANSWERS
Practice Problems:
Name the following compounds:
1.
BeO – Beryllium oxide
2.
Cs3N – Cesium nitride
3.
RbCl – Rubidium chloride
Determine the formula of the following compounds:
1.
Aluminum oxide – Al2O3
2.
Calcium bromide – CaBr2
3.
Lithium sulfide – Li2S
4.
Barium fluoride – BaF2
5.
Aluminum chloride – AlCl3
Practice Problems:
Name the following compounds:
1.
CrF2 – Chromium (II) fluoride
2.
NiO – Nickel (II) oxide
3.
Fe2O3 – Iron (III) oxide
4.
VCl – Vanadium (I) chloride
5.
SnO2 – Tin (IV) oxide
Determine the formula of the following compounds:
1.
Iron (III) sulfide – Fe2S3
2.
Lead (II) oxide – PbO
3.
Chromium (III) iodide – CrI3
4.
Copper (I) oxide – Cu2O
5.
Cobalt (II) nitride – Co3N2
Practice Problems:
Name the following compounds:
1.
Al(NO3)3 – Aluminum nitrate
2.
KMnO4 – Potassium permanganate
3.
FeSO3 – Iron (II) sulfite
4.
(NH4)3PO4 – Ammonium phosphate
5.
NaCN – Sodium cyanide
Determine the formula of the following compounds:
1.
Copper (II) nitrite – Cu(NO2)2
2.
Ammonium oxide – (NH4)2O
3.
Sodium hydroxide – NaOH
4.
Iron (III) chromate – Fe2(CrO4)3
5.
Calcium carbonate – CaCO3
Practice Problems:
Name the following compounds:
1.
P2O – Diphosphorus monoxide
2.
CO – Carbon monoxide
3.
C4Cl5 – Tetracarbon pentachloride
4.
SBr6 – Sulfur hexabromide
Determine the formula of the following compounds:
1.
Phosphorus triodide – PI3
2.
Sulfur dichloride – SCl2
3.
Dinitrogen pentoxide – N2O5
4.
Sulfur tetroxide – SO4
Calculate formula mass of a compound and convert from grams to moles or vise versa.
Practice Problems:
Convert the following:
1.25 moles of aluminum bromide  grams
1.25 mol AlBr3 266.694 g

= 333 g AlBr3
1
1 mol AlBr3
6.34 moles of iron (III) sulfate  grams
6.34 mol Fe2(SO4)3
399.88 g

= 2540 g Fe2(SO4)3
1
1 mol Fe2(SO4)3
76.4 grams of sodium hydroxide  moles
76.4 g NaOH 1 mol NaOH

= 1.91 mol NaOH
1
39.997 g
53.4 grams of sodium hydroxide  molecules
53.4 g NaOH 1 mol NaOH 6.022  1023 molecules


= 8.04  1023 molecules
1
39.997 g
1 mol
Calculate percent composition of a compound.
Practice Problems:
Determine the percentage composition of magnesium hydroxide.
Mg(OH)2
Mg = 41.67%
O = 54.87%
H = 3.46%
How many atoms of each element are contained in a single formula unit of iron (III)
formate, Fe(CHO2)3•H2O? What percentage by mass of the compound is water?
1 atom of Fe, 3 atoms of C, 5 atoms of H, 7 atoms of O
8.62%
Determine the empirical formula and molecular formula of a compound.
Practice Problems:
Determine the empirical formula of a compound found to contain 52.11% carbon,
13.14% hydrogen, and 34.75% oxygen.
C2H6O
A 1.344 g sample of a compound contains 0.365 g Na, 0.221 g N, and 0.758 g O. What
is its empirical formula?
NaNO3
The molar mass of a compound is 92 g/mol. Analysis of a sample of the compound
indicates that it contains 0.606 g N and 1.390 g O. Find its molecular formula.
N2O4
A hydrate of Na2SO3 contains almost exactly 50% H2O by mass. What is the formula for
this hydrate?
Na2SO3 ∙ 7 H2O