CHM 1025C                                    Name: _________________
Module Five III Homework Packet

Module Five Part III: Chemical Equations & Stoichiometry (Chapter 9)

I.______(10) Mole-Mole Problems Sections 9.1-9.2 Answers ij

J._____ (10) Mass-Mass Stoichiometric Problems-Sections 9.3 & 9.4 Answers ij

K._____(05) Excess/Limiting Reagent Problems-Section 9.7-9.8 Answers kl

L._____ (05) Per Cent Yield Problems/Impure Reagents-Section 9.9

______(30) Total  

Module Five III Chapter 9 Sections 9.1-9.2
see worked Example 9.2 page 253
additional Suggested Problems: Pages 273-274 #7-12
Part I  Mole-Mole Stoichiometry       10 points

Homework #1: Tungsten occurs in the important mineral sheelite (Calcium tungstate), which is converted to tungstic acid.  Tungsten is then extracted from tungstic acid by the following (unbalanced) reaction:    

                    H2   +       H2WO4      à        W        +        H2O

How moles of hydrogen is needed to prepare 6 moles of elemental tungsten?

 

 

 

 

Homework #2: Phosphoric acid can be made by the following (unbalanced) reacti

 H2O               +             P4O10     à              H3PO4

How many moles of Phosphoric acid can be prepared from the combination of 5 moles of Tetraphosphorus decoxide with excess water?      

 

 

 

 

 

Module Five III Chapter 9 Sections 9.4
see worked Examples 9.4 page 256 and 9.5 page 257
additional Suggested Problems: Page 274 #19-28
Part J  Mass-Mass Stoichiometry       10 points

Homework #3: Toluene and nitric acid are used in the production of trinitrotoluene (TNT), an explosive:

C7H8      +   HNO3       à      C7H5N3O6      +     H2O      (Unbalanced)

Calculate the mass of TNT that can be made from 192 g of C7H8 (toluene).

 

 

 

 

 

 

 

 

 

Homework #4: What mass of carbon dioxide is produced from the combustion of 176 grams of propane gas ,  C3H8 , in excess oxygen gas,  O2.  Water is the only other product.

 

 

 

 

 

 

 

 

 

Skip Sections 9.5 and 9.6 until Module 6

Module Five III Chapter 9 Sections 9.7-9.8
see worked Examples 9.9 page 265 and 9.10 page 267
additional Suggested Problems: Page 275-6 Concept #49-58-Problems #59-74
Part K Excess-Limiting Reagent Problem         5 points

Homework #5: How many grams of Calcium phosphate can be made according to the reaction (unbalanced):

 

   CaCl2       +     K3PO4     ---->        Ca3(PO4)2        +   KCl

 

by mixing a solution of 5.00 grams of CaCl2   with another containing 8.00 grams of Potassium phosphate?

 

 

 

 

 

 

Module Five III Chapter 9 Sections 9.9
see worked Examples 9.12 page 270-271
additional Suggested Problems: Page 276-7 #75-78
Part L Impure Reagents/Percent Yield Problem         5 points

Homework #6: A laboratory manual calls for 13.0 grams of butanol reactant in excess sodium bromide and sulfuric acid as reactants in this reaction:

C4H9OH   +   NaBr     +     H2SO4   ------>     C4H9Br   +   NaHSO4    +   H2O

 

A student following these directions obtains 16.8 grams of butyl bromide (C4H9Br).   What is the theoretical yield and the percent yield of this reaction?