Ch.12 - SolutionsSee all chapters
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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

Mole Fraction (X) relates the moles of solute and solvent within a solution. 

Understanding Mole Fraction

Concept #1:

Mole Fraction is depicted as moles of solute per moles of solution. 

 

Example #1: If the mole fraction of glucose, C6H12O6, in an aqueous solution is 0.320 what is the molarity? Density of the solution is 1.530 g/mL. 

Example #2: If the mole fraction of methanol, CH3OH, in an aqueous solution is 0.060 what is the molality? Density of the solution is 1.39 g/mL. 

Example #3:

Calculate the mole fraction of acetic acid, HC2H3O2, in a 27.13 mass % aqueous solution (d = 0.9883 g/mL). MW of HC2H3O2 is 60.054 g/mol. 

 

Additional Problems
What is the mole fraction of methanol, CH 3OH, if 55.18 g of methanol are added to 208.00 g of water?A. 0.633B. 0.130C. 8.277D. 0.149E. 0.321
Determine the mole fraction of glucose, C6H12O6, (molecular weight 180.18) in a 1.86 M aqueous glucose solution given the density of the glucose solution is 1.38 g/cm3.a. 0.0311b. 0.0237c. 0.0324d. 0.0243e. 0.0480
What is the mole fraction of ethanol, C 2H5OH, if 42.52 g of ethanol is added to 125.00 g of water?a. 0.480 b. 7.382c. 0.133d. 0.117e. 0.465
Calculate the mole fraction of total ions in an aqueous solution prepared by dissolving 0.400 moles of MgCl2 in 850.0 g of water.A. 0.00841B. 0.0270C. 0.00900D. 0.0248E. 0.0167
A solution is prepared by dissolving 38.6 g sucrose (C12H22O11) in 495 g of water.  Determine the mole fraction of sucrose if the final volume of the solution is 508 mL
What is the mole fraction of Ethanol in a solution composed of 10 g Ethanol (C  2H6O), 10 g H2O, & 10 g CH3OH? A) 0.217B) 0.201C) 0.33D) 0.289E) 0.410
A solution is made by mixing equal masses of methanol, CH 4O, and ethanol, C2H6O.Determine the mole fraction of each component to at least three significant figures.
A solution is prepared by dissolving 28.4 g of glucose (C 6H12O6) in 355 g of water . The final volume of the solution is 378 mL. For this solution, calculate the concentration in each unit.a. Molarityb. Molalityc. Percent by massd. Mole fractione. Mole percent
If the mass of sodium chloride, NaCl (MW = 58.5 g/mol), is 40.0 g and the mass of water is 30.0 g, what is the mole fraction of NaCl in the solution?a. 0.291b. 0.60c. 0.40d. 40.0e. 0.240     What is the mass percent of NaCl in the solution in the previous question?a. 0.291b. 0.60c. 0.40d. 40.0e. 0.240
What is the mole fraction of NaCl in a solution that contains 40.0 g NaCl and 60.0 g H2O?a) none of the given answersb) 3.33c) 0.205d) 0.170e) 0.300
In a 66.0-g aqueous solution of methanol, CH 4O, the mole fraction of methanol is 0.120. What is the mass of each component?a) Mass of CH4Ob) Mass of water
A solution is prepared by dissolving 38.6 g sucrose (C12H22O11) in 495 g of water.  Determine the mole fraction of sucrose if the final volume of the solution is 508 mL.A) 1.28 × 10 -3      B) 2.45 × 10 -3 C) 7.80 × 10 -2D) 4.09 × 10 -3 E) 7.23 × 10 -2
A solution was prepared by dissolving 39.0 g of KCl in 225 mL of water. Calculate the mole fraction of the ionic species KCl in the solution. Express the concentration numerically as a mole fraction in decimal form.
Which of the following chemical terms is affected by temperature? MolalityMass percentMolarityMole fraction
What does each of the following statements mean? a.) 1.80 M NaCl    b.) 39 percent by mass HBr   c.) CO2 has a mole fraction of 0.310 in aqueous solution             d.) 1.25 m KOCH2CH3   e.) 45 percent by volume NO3 
A solution is made by mixing equal masses of methanol CH 4O (MW = 32.01 g/mol) and ethanol C2H6O (MW = 46.02 g/mol). Determine the mole fraction of methanol. a) 0.129 b) 0.388c) 0.410d) 0.590
What is the mole fraction of water in 200 g of 95% (by mass) ethanol, C 2H5OH?Formula Molar Mass of C2H5OH is 46 g•mol –1.a) 0.050b) 0.12c) 0.56d) 0.88
If the mass of sodium chloride, NaCl (MW= 58.5 g/mol), is 40.0 g and the mass of water is 30.0 g, what is the mole fraction of NaCl in the solution? a) 0.291 b) 0.60 c) 0.40 d) 40.0 e) 0.240   What is the mass percent of NaCl in the solution in the previous question? a) 0.291 b) 0.60 c) 0.40 d) 40.0 e) 0.240
A concentrated solution of glucose (C6H12O6) in water 75.3 % glucose by mass. Calculate the mole fraction and the molarity of glucose solution. (The density of the solution is 1.03g/mL)
What are the mole fractions of H3PO4 and water in a solution of 14.5 g of H3PO4 in 125 g of water?(a) Outline the steps necessary to answer the question.(b) Answer the question.
What are the mole fractions of HNO3 and water in a concentrated solution of nitric acid (68.0% HNO3 by mass)?(a) Outline the steps necessary to answer the question.(b) Answer the question.
Calculate the mole fraction of each solute and solvent:(a) 583 g of H2SO4 in 1.50 kg of water—the acid solution used in an automobile battery
Calculate the mole fraction of each solute and solvent:(b) 0.86 g of NaCl in 1.00 × 102 g of water—a solution of sodium chloride for intravenous injection
Calculate the mole fraction of each solute and solvent:(c) 46.85 g of codeine, C18H21NO3, in 125.5 g of ethanol, C2H5OH
Calculate the mole fraction of each solute and solvent:(d) 25 g of I2 in 125 g of ethanol, C2H5OH
Calculate the mole fraction of each solute and solvent:(a) 0.710 kg of sodium carbonate (washing soda), Na2CO3, in 10.0 kg of water—a saturated solution at 0 °C
Calculate the mole fraction of each solute and solvent:(b) 125 g of NH4NO3 in 275 g of water—a mixture used to make an instant ice pack
Calculate the mole fraction of each solute and solvent:(c) 25 g of Cl2 in 125 g of dichloromethane, CH2Cl2
Calculate the mole fraction of each solute and solvent:(d) 0.372 g of tetrahydropyridine, C5H9N, in 125 g of chloroform, CHCl3
Calculate the mole fractions of methanol, CH3OH; ethanol, C2H5OH; and water in a solution that is 40% methanol, 40% ethanol, and 20% water by mass. (Assume the data are good to two significant figures.)
A gas mixture contains 0.60 mol of N2, 0.40 mol of H2, and 0.25 mol of CH4. What is the mole fraction of H2 in the mixture?
What is the mole fraction of oxygen gas in air (see the table on the left)?
An aqueous solution contains 56% NaCl by mass.Part ACalculate the molality of the solution. Express your answer using two significant figures. Part B Calculate mole fraction of the solution.Express your answer using two significant figures. 
In a mixture of argon and hydrogen, occupying a volume of 1.66 L at 910.0 mmHg and 54.9°C, it is found that the total mass of the sample is 1.13 g. What is the partial pressure of argon? (a) 455 mmHg (b) 319 mmHg (c) 866 mmHg (d) 591 mmHg (e) 43.7 mmHg
A solution is made by mixing 109. g of acetyl bromide (CH3COBr) and 70. g of thiophene (C4H4S). Calculate the mole fraction of acetyl bromide in this solution. Be sure your answer has the correct number of significant digits.
What is the mole fraction of O2 in this mixture? 12.3 g of CO2 and 38.2 g of O2.
A solation is prepared by dissolving 15.0 g of NH3, in 250.0 g of water. The density of the resulting solution is 0.974 g/mL. The mole fraction of NH3 in the solution is ________.(i) 0.0597 (ii) 0.0640 (iii) 16.8 (iv) 0.940 (v) 0.922
A 10.00 L tank at 0.8 degree C is filled with 16.8 g of dinitrogen difluoride gas and 13.2 g of sulfur hexafluoride gas. You can assume both gases behave as ideal gases under these conditions. Calculate the mole fraction of each gas. Round each of your answers to 3 significant digits.  
What is the mole fraction of lead(II) nitrate in an aqueous solution prepared by dissolving 25.4 g of the solute in 150 0 mL of water at 22°C? The density of water at 22°C is 0.998 g/mL.
A gaseous mixture contains 406.0 Torr of H2(g), 347.9 Torr of N2 (g), and 83.1 Torr of Ar(g). Calculate the mole fraction, X, of each of these gases.XH2 =XN2 =XAr =  
A 5.00 L tank at 30.7°C is filled with 15.2 g of boron trifluoride gas and 10.4 g of sulfur hexafluoride gas. You can assume both gases behave as ideal gases under these conditions. Calculate the mole fraction of each gas. Be sure each of your answer entries has the correct number of significant digits.
A solution is made by mixing 141. g of heptane (C7H16) and 121. g of chloroform (CHCl3) Calculate the mole fraction of heptane in this solution. Round your answer to 3 significant digits.