Ch.3 - Chemical ReactionsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Solution: An iron ore sample contains Fe2O3 plus other impurities. A 752-g sample of impure iron ore is heated with excess carbon, producing 453 g of pure iron by the following reaction:Fe2O3 (s) + 3 C (s) → 2 Fe (s) + 3 CO (g)What is the mass percent of Fe 2O3 in the impure iron ore sample? Assume that Fe 2O3 is the only source of iron and that the reaction is 100% efficient.

Solution: An iron ore sample contains Fe2O3 plus other impurities. A 752-g sample of impure iron ore is heated with excess carbon, producing 453 g of pure iron by the following reaction:Fe2O3 (s) + 3 C (s) → 2

Problem

An iron ore sample contains Fe2O3 plus other impurities. A 752-g sample of impure iron ore is heated with excess carbon, producing 453 g of pure iron by the following reaction:

Fe2O3 (s) + 3 C (s) → 2 Fe (s) + 3 CO (g)

What is the mass percent of Fe 2O3 in the impure iron ore sample? Assume that Fe 2O3 is the only source of iron and that the reaction is 100% efficient.

Solution

The mass percentage of pure Fe2O3 can be computed using the equation: 


Since the reaction is 100% efficient this means that all Fe2O3 in the iron ore reacted to form pure Fe.


The mass of impure Fe2Oor the mass of the iron ore sample is already given as 752 g


But, the mass of pure Fe2Oneeds to be calculated based on the moles of Fe produced in the reaction.


We can solve for the Mass of Fe2O3 through the following steps:

  1. mass to mole calculation (converting mass of Fe to moles)  
  2. mole to mole calculation (moles Fe to moles Fe2O3 )
  3. mole to mass calculation (converting moles to mass of Fe2O3)
Solution BlurView Complete Written Solution