MOLE & NOMENCLATUREPROBLEM SET

1. Mole Conversion Practice

  1. 2.5 moles of hydrochloric acid would have a mass of ______.
  1. 1.204 x 1024 molecules of nitrogen dioxide would have a mass of ______.
  1. 2.5 moles of perchloric acid would contain ______molecules.
  1. 1.204 x 1024 molecules of tricarbonoctahydride would contain ______moles.
  1. 42 grams of nitrogen would have ______molecules.
  1. 2.406 x 1024 molecules of chloric acid would have a mass of ______.
  1. 4.24 moles of magnesium chloride contain ______chloride ions.
  1. 3.5 x 1022 formula units of iron(III) sulfite has a mass of ______.
  1. 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. 91g2. 92.02g3. 1.5 x 1024 molecules4. 2.000mol5. 9.0 x 1023 molecules 6. 337.6g 7. 5.10 x 1024 ions Cl- 8 20.g 9. 1.63 x 1024 atoms 10. 460. g/mol

PERCENT COMPOSITION, EMPIRICAL FORMULA AND MOLECULAR FORMULA

Find the percent composition of:

  1. sulfurous acid
  1. zinc phosphate

Using percent composition:

  1. Determine the mass of phosphorus in 23.1g of zinc phosphate.
  1. What mass of zinc phosphate contains 4.50g of phosphorus?

Find the empirical formula of a compound that is:

  1. 88.8% copper; 11.2% oxygen
  1. 40.0% carbon; 6.7% hydrogen; 53.3% oxygen
  1. 14.88% nitrogen; 85.12% sulfur
  1. 19.81% carbon; 2.22% hydrogen; 77.97% chlorine

Molecular Formula

  1. 27.3% carbon; 72.7% oxygen; experimental molar mass is 132 g/mol.
  1. 92.3% carbon; 7.7% hydrogen; experimental molar mass is 78.1 g/mol.

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 anacidwith 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%O2. 50.80% Zn, 16.04%P, 33.15%O3. 3.71gP 4. 28.1g Zn3(PO4)25. Cu2O

6. CH2O 7. N2S5 8.. C3H4Cl4 9. C3O6 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/cm3)

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 mass19.90 g

crucible + hydrate21.05g

crucible + anhydrous compound20.99 g

Answers: 1. 2110g CuI22. 24.3g/mol3. 19.3g/cm34. 5.01 x 1023 molecules5. 31.3g/mol

6. 8.76 X 1023 atoms 7. 38.7 g/mol 8. 263 cm3 9. Fe2O3 10. Pb(C2H3O2)21H2O

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Nomenclature Workout:

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1.Name these ionic compounds by putting together cation and anion names.

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  1. CaCl2

  1. BaSO4

  1. NaNO3

  1. MgO

  1. LiOH

  1. ZnCO3

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2. Name these ionic compounds with transition metals. Use Roman numerals in parentheses to show charge of cation.

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  1. FeSO4

  1. Fe2(C2O4)3

  1. SnO

  1. SnO2

  1. CuIO4

  1. Cu2SO4

  1. Pb(ClO2)2

  1. Pb(ClO2)4

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** two possible names

3.Write a balanced formula for each compound.

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  1. tin(II) fluoride

  1. tin(IV) oxide

  1. tin(IV) peroxide

  1. iron(III) peroxide

  1. zinc oxide

  1. silver cyanide

  1. ammonium hydroxide

  1. sodium hydrogen carbonate

  1. calcium hypochlorite

  1. tin(II) thiocyanate

  1. zinc sulfate

  1. cobalt(II) phosphate

  1. chromium(III) sulfite

  1. silver permanganate

  1. aluminum carbonate

  1. calcium perchlorate

  1. sodium acetate

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4.Determine which of these compounds will need Roman numerals in their names. Name each compound.

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  1. CaSO4

  1. Fe(NO2)3

  1. Na3AsO4

  1. (NH4)2Cr2O7

  1. Li2O2

  1. CrI3

  1. Cd3P2

  1. Sn(SO3)2

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5. Write formulas for these molecular compounds

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  1. carbon monoxide

  1. nitrogen tribromide

  1. diphosphorouspentoxide

  1. tricarbontetranitride

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6.Name these acids using hydro,-ic or-ous as needed.

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  1. H3PO3

  1. H2CrO4

  1. H2CO3

  1. HF

  1. HClO

  1. H2Cr2O7

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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

  1. PCl5

  1. CuClO3

  1. H2SO3

  1. SeF6

  1. Cr(HCO3)2

  1. AlPO4

  1. N2O4

  1. Ag3N

  1. 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. tricarbonhexahydride
3. copper(I) phosphite
4. hydroarsenic acid
5. periodic acid
6. diphosphoruspentoxide
  1. nitrous acid

  1. zinc peroxide

  1. trisilicontetrantride

  1. hydronitric acid

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