MOLE & NOMENCLATURE PROBLEM SET
1. Mole Conversion Practice
1.
2.5 moles of hydrochloric acid would have a mass of ____________.
2.
1.204 x 1024 molecules of nitrogen dioxide would have a mass of ______.
3.
2.5 moles of perchloric acid would contain ___________ molecules.
4.
1.204 x 1024 molecules of tricarbon octahydride would contain __________ moles.
5.
42 grams of nitrogen would have __________ molecules.
6.
2.406 x 1024 molecules of chloric acid would have a mass of ________.
7.
4.24 moles of magnesium chloride contain ____________ chloride ions.
8.
3.5 x 1022 formula units of iron(III) sulfite has a mass of ____________.
9.
15.2L of methane gas, (CH4), at STP, contains ___________ hydrogen atoms.
**10. The molar mass of a substance is given in g/mol. Find the molar mass of a substance if 2.25 x 1022 formula
units of the substance has a mass of 17.2g.
Answers: 1. 91g 2. 92.02g
3. 1.5 x 1024 molecules
6. 337.6g
7. 5.10 x 1024 ions Cl8 20.g
4. 2.000mol
9. 1.63 x 1024 atoms
5. 9.0 x 1023 molecules
10. 460. g/mol
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PERCENT COMPOSITION, EMPIRICAL FORMULA AND MOLECULAR FORMULA
Find the percent composition of:
1. sulfurous acid
2. zinc phosphate
Using percent composition:
3. Determine the mass of phosphorus in 23.1g of zinc phosphate.
4. What mass of zinc phosphate contains 4.50g of phosphorus?
Find the empirical formula of a compound that is:
5. 88.8% copper; 11.2% oxygen
6. 40.0% carbon; 6.7% hydrogen; 53.3% oxygen
7. 14.88% nitrogen; 85.12% sulfur
8.
19.81% carbon; 2.22% hydrogen; 77.97% chlorine
Molecular Formula
9. 27.3% carbon; 72.7% oxygen; experimental molar mass is 132 g/mol.
10. 92.3% carbon; 7.7% hydrogen; experimental molar mass is 78.1 g/mol.
2
11. 94.12% sulfur; 5.88% hydrogen; experimental molar mass is 34.1 g/mol.
12.
74.02% carbon; 8.71% hydrogen; 17.27% nitrogen; experimental molar mass is 162.2 g/mol.
13. a. What is the empirical formula of an acid with 0.176g hydrogen, 5.61g sulfur and 4.21g oxygen?
b. Name the acid. (S2O32- is called thiosulfate).
14. A 1.000 g sample of a compound composed of iron and oxygen contains 0.7236 g of iron. Determine the empirical
formula of the compound.
Answers: 1. 2.46% H, 39.06%S, 58.48%O
6. CH2O 7. N2S5
8.. C3H4Cl4 9. C3O6
2. 50.80% Zn, 16.04%P, 33.15%O
3. 3.71gP
4. 28.1g Zn3(PO4)2
5. Cu2O
10. C6H 11. H2S
12. C10H14N2 13. H2S2O3 (thiosulfuric acid) 14. Fe3O4
Mixed Mole Problems
1. How many grams of copper (II) iodide are needed to get 8.00 X 1024 iodide ions?
2. If an element has 1.96 X 1022 atoms in 0.791 grams, what is its molar mass?
3. Find the density of gold in g/cm3 containing 3.77 X 1024 atoms in a cube measuring 0.787 inch by 3.15 inch by 1.57
inch. (1 inch = 2.54 cm)
4. How many molecules of water would there be in 15.0 mL? (The density of water is 1.00g/cm 3)
3
5. 14.25g of a gas occupies 10.2L at STP. Find the molar mass of the gas.
6. How many hydrogen atoms are in 8.25 grams of ammonia (NH3)?
7. What is the molar mass of a compound containing 2.25 X 1023molecules in 14.45 grams?
8. Lead has a density of 12.3 g/cm3. How many what volume would 9.40 X 1024 atoms occupy?
9. Use the following data to find the empirical formula of this compound:
crucible mass
15.00 g
crucible + iron
24.68 g
crucible + iron oxide compound
28.85 g
10. Use the following data to find the formula of this lead(II) acetate hydrate:
crucible mass
19.90 g
crucible + hydrate
21.05g
crucible + anhydrous compound 20.99 g
Answers: 1. 2110g CuI2
2. 24.3g/mol
3. 19.3g/cm3
4. 5.01 x 1023 molecules
6. 8.76 X 1023 atoms
7. 38.7 g/mol
8. 263 cm3
9. Fe2O3
5. 31.3g/mol
10. Pb(C2H3O2)21H2O
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Nomenclature Workout:
1.
Name these ionic compounds by putting together cation and anion names.
1. CaCl2
4. MgO
2. BaSO4
5. LiOH
3. NaNO3
6. ZnCO3
2. Name these ionic compounds with transition metals. Use Roman numerals in parentheses to show
charge of cation.
1. FeSO4
5. CuIO4
2. Fe2(C2O4)3
6. Cu2SO4
3. SnO
7. Pb(ClO2)2
4. SnO2
** two possible names
8. Pb(ClO2)4
3.
Write a balanced formula for each compound.
1. tin(II) fluoride
2. tin(IV) oxide
10. tin(II) thiocyanate
3. tin(IV) peroxide
11. zinc sulfate
4. iron(III) peroxide
12. cobalt(II) phosphate
5. zinc oxide
13. chromium(III) sulfite
6. silver cyanide
14. silver permanganate
7. ammonium hydroxide
15. aluminum carbonate
8. sodium hydrogen carbonate
16. calcium perchlorate
9. calcium hypochlorite
17. sodium acetate
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4. Determine which of these compounds will need Roman numerals in their names. Name each compound.
1. CaSO4
5. Li2O2
2. Fe(NO2)3
6. CrI3
3. Na3AsO4
7. Cd3P2
4. (NH4)2Cr2O7
8. Sn(SO3)2
5. Write formulas for these molecular compounds
1. carbon monoxide
3. diphosphorous pentoxide
2. nitrogen tribromide
4. tricarbon tetranitride
6.
Name these acids using hydro,- ic or- ous as needed.
1. H3PO3
2. H2CrO4
3. H2CO3
4. HF
5. HClO
6. H2Cr2O7
7. Write the formula for each acid below:
a. chloric acid
_____________________________
b. permanganic acid
_____________________________
c. phosphorous acid
_____________________________
d. hydrophoshoric acid
_____________________________
e. hydrocyanic acid
_____________________________
f.
_____________________________
acetic acid
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9.
First determine whether the compound is ionic, molecular or acidic; then name each accordingly:
I ,M or A
Name
1.
Ca(ClO4)2
2.
PCl5
3.
CuClO3
4.
H2SO3
5.
SeF6
6.
Cr(HCO3)2
7.
AlPO4
8.
N2O4
9.
Ag3N
10.
H2CrO4
10.
First determine whether the compound is ionic, molecular or acidic; then write the formula accordingly:
I ,M or A
Formula
1. aluminum sulfite
2. tricarbon hexahydride
3. copper(I) phosphite
4. hydroarsenic acid
5. periodic acid
6. diphosphorus pentoxide
5.
nitrous acid
6.
zinc peroxide
7.
trisilicon tetrantride
8.
hydronitric acid
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