Module 5 Sample Exam

Part I Mole-Mole Stoichiometry 4 points


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 W + H2O


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
















Phosphoric acid can be made by the following (unbalanced) reaction:


H2O + P4O10 H3PO4


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














Module 5 Sample Exam

Module Five-Part J Mass-Mass Stoichiometry 4 points


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


C7H8 + HNO3 C7H5N3O6 + H2O (Unbalanced)


Calculate the mass of TNT that can be made from 126 g of C7H8 (toluene).















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.