Converting in the Mole
Name ___________________
1. Convert the following to comparable units and arrange from the smallest to the largest
number of particles.
a. 1.25 x 1025 atoms Zn
b. 3.56 mol Fe
c. 6.78 x 1022 molecules of glucose (C6H12O6)
2. Determine the number of particles in each of the following and identify the particle type
(atom, formula unit, or molecule).
a. 11.5 mol Ag
b. 18.0 mol water
c. 0.150 mol NaCl
3. How many moles are in 5.58 x 1022 formula units CaCl2
4. Calculate the number of molecules in 9.52 mol ammonia.
5. How many moles are in 1.11 x 1024 atoms Sn
Mass and the Mole
1. What is the mass of a dozen limes?
Eggs?
Why are they different?
2. If you had a mole of carbon and a mole of copper atoms, would there mass be
the same or different?? Why?
3. True or False -
The mass of an atom of helium-4 is 4 amu.
4. What is molar mass?
5. If you have 1 mole of manganese how many atoms of manganese do you have:
Use dimensional analysis to solve the following problems.
6. Determine the mass in grams of 3.57 mol Al:
7. Calculate the number of moles in 25.5 g Ag
Measuring Matter
1. What is a mole? One mole contains how many particles?
2. Avogadro’s Number =
________________________
In Column B, rank the quantities from Column A from the smallest to the largest.
Column A
Column B
0.5 mol
6._____________________________
200
7. _____________________________
5
8. _____________________________
6 000 000 000
9. _____________________________
6.02 x 1023
10. ____________________________
Dozen
11. ____________________________
Four moles
12. ____________________________
Gross equal to a dozen dozen( 12x12= ? )
13. ____________________________
Pair
14. ____________________________
Moles of Compounds
The Molar Mass of Compounds
1. The mass of your backpack=
2. The mass of a mole of a compound equals what?
3. Determine the molar mass of the following ionic compounds:
a. NaOH
b. (NH4)3PO4
4. Determine the molar mass of the following molecular compounds
a. C2H5OH
b. C12H22O11(sugar)
Molar Mass
5. Determine the molar mass for each of the following compounds. Show your work.
6. 1. CaCl2
5. Ammonium Phosphate
7. 2. Zinc Chloride
6. C2H5OH
8. 3. C12H22O11 (sucrose)
7. Carbon Tetrachloride
9. 4. Water
8. Copper (II) sulfate
Converting
1.
Determine the mass in grams of 3.57 mol Ag.
2.
What is the mass of 4.55 moles of water?
3.
Determine the number of moles in 25.0 g sucrose.
4.
What is the mass of 5.35 x 10-2 moles of zinc chloride (ZnCl2)?
5.
Determine the number of moles in each of 23.7 g S.
6.
How many moles are in 45.0 g CaCl2
7. The mass of a single atom is usually given in the unit amu. It is possible to express the
mass of a single atom in grams. Let’s do it! What is the mass of 1 atom of copper?
8. Arrange the following in order from smallest to largest moles.
a. 1.0 mol Ar
b. 6.0 x 1024 atoms Ne
c. 20.0 g Kr
9. How many atoms are in 766.3 g Li?
10. What is the mass in grams of 8.62 x 1024 atoms Mn?
11. How many grams are in 2.34 mol Co?
12. A sample of ethanol (C2H5OH) has a mass of 45.6 g. How many molecules are in the
sample?
Converting between all units – additional practice
1. How many atoms are in 4.25 mol Zn?
2. How many moles are in 300.0 g Zn?
3. What mass of ammonium phosphate contains 4.76 x 1024 formula units?
4. A sample of carbon tetrachloride has a mass of 2.25 g. How many particles are in the
sample?
5. What is the mass of 0.251 moles of Aluminum phosphate?
6. A sample of carbon tetrabromide has a mass of 125 g. How many particles are in the
sample?
Empirical and Molecular Formulas
1. Calculate the percent composition of water. Show your work.
Empirical Formula
2. What is an Empirical Formula? And what information do you need to know to
determine the empirical formula?
3. What is the empirical formula for hydrogen peroxide?_____________
4. What is the molecular formula?
What is the ratio of oxygen to
hydrogen?
5. You have determined that a compound is composed of 0.300moles of carbon
and 0.600 moles of oxygen. What must you do to determine the mole ratio of the
elements in the empirical formula of the compound?
a. Multiply each mole value by 0.300 mol
mol
b. Mutiply each mole value by 0.600 mol
mol
c. Divide each mole value by 0.300
d. Divide each mole value by 0.600
6. The mole ratio of carbon to hydrogen to oxygen in a compound is 1mol C: 2 mol
H: 1 mol O. What is the empirical formula of the compound?
a. CHO
b. CH2O
c. C2HCO2
d. C2H2O2
7. You calculate the mole ratio of oxygen to aluminum in a compound to be 1.5
mol O: 1 mol Al. What should you do to determine the mole ratio in the empirical
formula of the compound?
a. Multiply each mole value by 1.5.
b. Multiply each mole value by 2.
c. divide each mole value by 1.5.
d. Divide each mole value by 2.
8. What is the relationship between the molecular formula and the empirical
formula of a compound?
9. You know that the experimental molar mass of a compound is three times the
molar mass of its empirical formula. If the compound’s empirical formula is NO2,
what is its molecular formula?
10. A sample of a compound contains 7.89g potassium, 2.42g carbon, and 9.69 g
oxygen. Determine the empirical and molecular formulas of this compound,
which has a molar mass of 198.22 g/mol. Show your work.
Empirical Formulas
1. What is an empirical formula?
2. A blue solid is found to contain 36.84% nitrogen and 63.16% oxygen. What is the empirical
formula for this solid?
3. What is the empirical formula for a compound that contains 10.89% magnesium, 31.77%
chlorine, and
57.34% oxygen?
4. Analysis of a compound composed of iron and oxygen yields 174.86 g Fe and 75.14 g O.
What is the empirical formula for this compound?
5. The pain reliever morphine contains 17.900 g C, 1.680 g H, 4.255 g O and 1.228 g N.
Determine the empirical formula.
6. A solid compound decomposes when heated in the laboratory. Given the following data,
determine the empirical formula for the initial compound.
Item
Crucible
Crucible and
Solid Reactant
Solid Reactant
Crucible and
Solid Product
Solid Product
Gas Product
Mass (g)
31.25
36.04
Reaction Equation
AxBy(s) ---------> xA(s) + yB(g)
35.45
The molar mass of element A is 84.0 g/mol
and element B is 23.7 g/mol.
7. Determine the empirical formula for a compound that contains 35.98% aluminum and 64.02%
sulfur.
8. The chemical analysis of aspirin indicates that the molecule is 60.00% carbon, 4.44%
hydrogen, and 35.56% oxygen. What is the empirical formula for aspirin?
9. When an oxide of potassium is decomposed, 19.55 g K and 4.00 g O are obtained. What is
the empirical formula for the compound?
10. Determine the empirical formula of a compound with 65.2% Sc and 34.8% O
11. Determine the empirical formula of a compound with 52.8% Sn, 12.4% Fe, 16% C and
18.8% N
Percent Yield, Empirical and Molecular Formulas Worksheet
Name:
Period:
1. a) What is the percent by mass of each element in K2CrO4?
b) What is the percent by mass of each element in K2Cr2O7?
c) Which of the above compounds had a greater percent by mass of
chromium?
2. a)Analysis of a compound indicates the percent composition 42.07% Na,
18.89% P, and 18.89% O. Determine the empirical formula of the substance.
b)A liquid was found to contain 39.12% C, 8.76% H, and 52.21 %O. Determine the
empirical formula of the substance.
3. Analysis of a compound reveals the compound contains 26.76% C, 2.20% H,
and 71.17% O and has a molar mass of 135.01g/mol. Determine the empirical
and molecular formula for this substance.
Empirical & Molecular Formulas
Name:
Period:
1. Determine the percent composition of each of the following compounds.
a) Manganese oxide (MnO)
b) Propanol (C3H8O)
c) Calcium phosphate (Ca3(PO4)2)
2. Determine the empirical formula for a sample of a compound having the
following percent composition 94.07% sulfur and 5.93% hydrogen.
3. Determine the empirical formula for a sample of a compound having the
following percent composition 80.68% mercury, 12.87% oxygen, and 6.54% sulfur.
4. Caffeine is a compound found in natural coffees and teas and in some soda
pops. Determine the empirical and molecular formula for caffeine, using the
following composition: 49.47% carbon, 28.85% nitrogen, 16.48% oxygen, and
5.20% hydrogen. The molar mass of caffeine is 194.19 g/mol.