Unit 6-Assignment Packet

Page #1 Molar Mass

Find the molar mass of each of the following compounds, YOU MUST SHOW ALL OF YOUR WORK OR IT WILL BE A (1) HOMEWORK CHECK:

1. H2SO4 2. H2O

3. H3PO4 4. Na3PO4

5. BaCl2 6. SO3

7. CCl4 8. Zn(OH)2

9. NH4CN 10. Pb(HCO3)4


Page #2 Percent Composition Problems

Solve the following problems showing all of your work:

1.  Calculate the percent composition by mass of each of the elements when reacting to form compounds according to the data.

A.  29.0 grams of Ag combines completely with 4.30 grams of S

B.  9.03 grams of Mg combines completely with 3.48 grams of N

C.  222.6 grams of Na combines completely with 77.4 grams of O

2.  Calculate the percent composition by mass of each of the elements in the following compounds according to their formulas.

A. C3H8 B. NaHSO4

C. Ca(C2H3O2)2 D. HCN

3.  Using your answers to problem #2 (A-D), calculate the amount of hydrogen in the following amounts of each compound.

A. 350 grams of C3H8 B. 20.2 grams of NaHSO4

C. 124 grams of Ca(C2H3O2)2 D. 378 grams of HCN

Page #3 Grams and Moles Conversions

Solve the following problems showing all of your work (POST AND MOLAR MASSES ROUNDED TO THE TENTHS PLACE)

1.  How many moles are there in 26.55 grams of water?

2.  How many grams are there in 1.475 moles of carbon dioxide gas?

3.  How many grams are there in 2.79 moles of carbon monoxide gas?

4.  How many moles are there in 357.2 grams of barium chloride solid?

5.  Which is has more mass 2 moles of calcium chloride or 3 moles of sodium chloride?


Page #4 Empirical Formual

Solve the following Empirical Formula problems. Show all of your work.

1.  What is the Empirical Formula of a compound that is found to be composed of 20.0g carbon, 6.71g hydrogen, 46.65g nitrogen, and 26.64g oxygen?

2.  What is the Empirical formula of a compound that has a percent composition of 17.01% Na, 47.46% S, and 35.57% O?

3.  What is the Empirical Formula of a compound that contains 82.98g of potassium and 17.02g of oxygen?

4.  What is the Empirical formula of a compound that is composed of 72.4g of Fe and 83.04g of O?

Page #5 Molecular Formula

Find the Molecular Formulas for each of the compounds from page #4. First transfer the Empirical Formula for each compound to this page. Next, show all of your work in determining the Molecular Formula.

1.  What is the Molecular Formula, knowing that the Molecular Formula Mass is 180.0 g/mole?

2.  What is the Molecular Formula, knowing that the Molecular Formula Mass is 270.0 g/mole?

3.  What is the Molecular Formula, knowing that the Molecular Formula Mass is 282.6 g/mole?

4.  What is the Molecular Formula, knowing that the Molecular Formula Mass is 119.8 g/mole?

Molecular/Formula Mass

Determine the molecular mass of each of the following by determining the mass of each atom in the molecule and adding them together. If a compound is in parenthesis and has a subscript, the subscript is added to all elements. Ex: Al(OH)3 Al – 1 O – 3 H - 3

Formula / Elements / Number of Atoms / Atomic Mass of the Elements / Formula Mass
CH4 / List the elements / Count the atoms / Round the mass / Finish the calculation here
H20 / List the elements / Count the atoms / Round the mass / Finish the calculation here
NO2 / List the elements / Count the atoms / Round the mass / Finish the calculation here
C3H8 / List the elements / Count the atoms / Round the mass / Finish the calculation here
CH3OOH / List the elements / Count the atoms / Round the mass / Finish the calculation here
HBr / List the elements / Count the atoms / Round the mass / Finish the calculation here
KBr / List the elements / Count the atoms / Round the mass / Finish the calculation here
LiOH / List the elements / Count the atoms / Round the mass / Finish the calculation here
Formula / Elements / Number of Atoms / Atomic Mass of the Elements / Formula Mass
Ba(OH)2 / List the elements / Count the atoms / Round the mass / Finish the calculation here
(NH4)2O / List the elements / Count the atoms / Round the mass / Finish the calculation here
CaCO3 / List the elements / Count the atoms / Round the mass / Finish the calculation here
NaNO3 / List the elements / Count the atoms / Round the mass / Finish the calculation here