Concept explainers
Dimethylglyoxime [DMG, (CH3CNOH)2] is used as a reagent to precipitate nickel ion. Assume that 53.0 g of DMC has been dissolved in 525 g of ethanol (C2H5OH).
s
The red, insoluble compound formed between nickel(II)ion and dimethylglyoxime (DMG) is precipitated when DMG is added to a bask solution of Ni2+ (aq).
- (a) What is the mole fraction of DMG?
- (b) What is the molality of the solution?
- (c) What is the vapor pressure of the ethanol over the solution at ethanol’s normal boiling point of 78.4 °C?
- (d) What is the boiling point of the solution? (DMG does not produce ions in solution.) (Kbp for ethanol = +1.22 °C/m)
(a)
Interpretation: Mole fraction of DMG has to be calculated.
Concept introduction:
Raoult’s law: In a solution, vapor pressure of solvent is proportional to its mole fraction.
where,
Mole fraction: Amount of that component divided by the total amount of all of the components of the mixture
Answer to Problem 57GQ
Mole fraction of DMG is
Explanation of Solution
Given,
The number of moles of any substance can be determined using the equation
Number of moles of dimethylglyoxime is,
Number of moles of ethanol is,
Mole fraction of DMG is calculated
Mole fraction of DMG is
(b)
Interpretation: Molality of the solution has to be determined.
Concept introduction:
Raoult’s law: In a solution, vapor pressure of solvent is proportional to its mole fraction.
where,
Mole fraction: Amount of that component divided by the total amount of all of the components of the mixture
Answer to Problem 57GQ
Molality of the solution is
Explanation of Solution
Given,
The number of moles of any substance can be determined using the equation
Number of moles of dimethylglyoxime is,
Molality of the solution is calculated
Molality of the solution is
(c)
Interpretation: Mole fraction of DMG and molality of the solution are to be determined. Vapour pressure of ethanol over the solution and Boiling point of the solution are to be calculated.
Concept introduction:
Raoult’s law: In a solution, vapor pressure of solvent is proportional to its mole fraction.
where,
Mole fraction: Amount of that component divided by the total amount of all of the components of the mixture
Answer to Problem 57GQ
Vapor pressure of ethanol over the solution is
Explanation of Solution
(c)
Given,
The number of moles of any substance can be determined using the equation
Number of moles of dimethylglyoxime is,
Number of moles of ethanol is,
Mole fraction of ethanol is
Vapour pressure of ethanol over the solution is calculated
Vapour pressure of ethanol over the solution is
(d)
Interpretation: Mole fraction of DMG and molality of the solution are to be determined. Vapour pressure of ethanol over the solution and Boiling point of the solution are to be calculated.
Concept introduction:
Raoult’s law: In a solution, vapor pressure of solvent is proportional to its mole fraction.
where,
Mole fraction: Amount of that component divided by the total amount of all of the components of the mixture
Answer to Problem 57GQ
Boiling point of the solution is
Explanation of Solution
(d)
Given,
Number of moles of dimethylglyoxime is,
Molality of the solution is calculated
Molality of the solution is
Elevation in boiling point of the solution is calculated
Therefore,
Boiling point of the solution is
Want to see more full solutions like this?
Chapter 13 Solutions
Chemistry & Chemical Reactivity
Additional Science Textbook Solutions
Organic Chemistry As a Second Language: Second Semester Topics
Organic Chemistry - Standalone book
The Organic Chem Lab Survival Manual: A Student's Guide to Techniques
Chemistry For Changing Times (14th Edition)
General Chemistry: Principles and Modern Applications (11th Edition)
General, Organic, and Biological Chemistry - 4th edition
- A solution contains 0.00740 M calcium ion. A concentrated sodium fluoride solution is added dropwise to precipitate calcium fluoride (assume no volume change). a At what concentration of F does precipitate start to form? b When [F] = 9.5 104 M, what is the calcium-ion concentration? What percentage of the calcium ion has precipitated?arrow_forwardHow do the concentrations of Ag+ and CrO42- in a saturated solution above 1.0 g of solid Ag2CrO4 Change when 100 g of solid Ag2CrO4 is added to the system? Explain.arrow_forwardA saturated solution of a slightly soluble electrolyte in contact with some of the solid electrolyte is said to be a system in equilibrium. Explain. Why is such a system called a heterogeneous equilibrium?arrow_forward
- The solubility of two slightly soluble salts of M2+ , MAand MZ2, is the same, 4 x 10-4 mol/L. (a) Which has thelarger numerical value for the solubility product constant?(b) In a saturated solution of each salt in water, which hasthe higher concentration of M2 + ? (c) If you added an equalvolume of a solution saturated in MA to one saturated inMZ2, what would be the equilibrium concentration of thecation, M2 + ?arrow_forwardThe apparent solubility products of AgCN and PBF2 at 25°C are 6.0x10¬1/ and 3.3x10-8, respectively. Calculate the solubility (g/100. g of solution) of these compounds. (Assume each solution has a density of 0.99705 g·cm-3.) solubility of AgCN 4.0 g/100. g of solution solubility of PbF2 4.0 g/100. g of solutionarrow_forward136 mL of 0.00015 M Pb(NO3)2 and 234 mL of 0.00028 M Na2SO4 (volumes are additive). Will a percipitate form? Hint: each solution dilutes the other upon mixing.arrow_forward
- solid P6CO3 is at equilibrium with its ions ? A) The concentration of CO ions in solution is is wrong for 500 mL of saturated solution in which 1.6 x 1015. Which one of the following statements 12. The solubility product for PbCO3 at 25°C is for 500 mL of saturated solution in which is wrong PbCO3 = 267 g/mol A) The concentration of CO3 ions in solution is %3D 4x10-8 M. B) The maximum mass of P6CO3 dissolved in solu- -3 tion is 5.34 x 10° mg. C) The solubility of P6CO3 at 25°C is 4 x 10-8 mol/L. D) The total number of ions in solution is 2.4x10-16. E) The concentration of each of Pb<+ and CO, ions at 50°C is 4 x 10-8 M.arrow_forward25. Which of the following has maximum solubility at low pH? (a) NH,CI (c) Na,PO4 (b) NaCl (d) Sr(OH),arrow_forwardDescribe what happens when (i) (NH4)2SO4 is added to a saturated solution of NH4Cl in water in the presence of excess NH4Cl, (ii) water is added to a mixture of 25 g of NH4Cl and 75 g of (NH4)2SO4.arrow_forward
- At approximately what temperature does the solubility of sodium chloride, NaCl, match the solubility of potassium dichromate, K,Cr,0,? 100 90 NaNO 80 70 60 50 KGI NaC 30 20 KCIO, 10 Ce,(SO) 0 10 20 30 40 50 60 70 80 90 100 Temperature (°C) O a 83 C 50 C 30 °C 60 °C Solubity (g of salt in t00 g H0) K Cr,O7arrow_forwardA solution is prepared by mixing 150.0 mL of 0.0010 M magnesium nitrate and 250.0 mL of 0.100 M sodium fluoride (Ksp = 7.4x10-11). What is the identify of the solid species? Write out the balanced equation for the solubility of the insoluble solid. Uses physical state symbols, an equal sign instead of a reaction arrow, and spaces where necessary. Example: (AgCl(s) = Ag+(aq) + Cl-(aq)) What is the value of the Qsp? Give your answer in exponential form and to three sig. figs. (e. g. 1.23E-3). THIS IS PART 1 WILL POST OTHER QUESTIONS AS PART 2arrow_forwardThe apparent solubility products of AgCN and PbF2 at 25°C are 6.0x10-1/ and 3.3×10¬8, respectively. Calculate the solubility (g/100. g of solution) of these compounds. (Assume each solution has a density of 0.99705 g·cm-3.) 4.0 solubility of A9CN g/100. g of solution solubility of PBF2 4.0 g/100. g of solutionarrow_forward
- Principles of Modern ChemistryChemistryISBN:9781305079113Author:David W. Oxtoby, H. Pat Gillis, Laurie J. ButlerPublisher:Cengage LearningGeneral Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage LearningChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage Learning
- Chemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning