Stoichiometry Answers

Unit 6: Chemical Reactions and Stoichiometry                                                                                    Reading: Chapter 12
Working Mode: Pairs                                                                                           Guided Instructional Activity 6-4

Learning Objective: To use the stoichiometric coefficients of the balanced chemical equation along with molar mass to solve stoichiometry problems.

The balanced reaction shown has been used to refine iron ore in the past.  The molar masses are
Fe₂O₃ -160 g/mol ; C-12.0 g/mol;  Fe-55.85 g/mol; CO₂ -44.0 g/mol

                                                2 Fe₂O₃(s)+ 3 C(s) à 4 Fe(s) + 3 CO₂(g)

 A reaction as represented by the equation above uses up 24.0 g Fe₂O₃ .  Answer each step below.  Ultimately this will allow you to determine what mass (g) of carbon (C) was needed to react with the Fe₂O₃, what mass (g) of iron and what volume (mL) of CO₂ measured at STP was produced.  Remember, one mol of a gas at STP occupies 22.4 L. Show all work in detail.

Steps

Student1: Find the mole of iron (III) oxide that reacted  (Answer: 0.150 mol)

Student2: Find the mol of carbon needed to react with the iron (III) oxide.  (Answer: 0.225 mol)

Student1: Find the mass (g) of carbon needed to react with the iron (III) oxide.  (2.70 g C)

Student2: Find the mol of iron produced.  (Answer: 0.300 mol)

Student1: Find the mass (g) of iron produced.  (Answer: 16.8 g Fe)

Student2: Find the mol of carbon dioxide produced.  (Answer: 0.225 mol CO₂)

Student1: Find the volume (mL) of carbon dioxide that formed  (Answer: 5040 mL)

Student2: Find the mass (g) of carbon dioxide produced.  (Answer: 9.90 g)