(3) A 300.0 mg sample of caffeine was dissolved in 10.0 g of camphor (K+= 39.7°C/kgmol.) The freezing point of camphor decreases by 3.07 °C. What isthe calculated molar mass of caffeine? Show your work. (4) Compare the calculated molar mass of caffeine with the known molar massof caffeine. Based on this information, what should be van't Hoff factor befor caffeine? Explain.

(3). To calculate the molar mass of caffeine, we can use the freezing point depression…

Answered: (3) A 300.0 mg sample of caffeine was…

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

See similar textbooks

Similar questions

A solution is prepared by dissolving 40.00 g of NaCl (f.w. = 58.44 g mol–1), a non-volatile solute, in enough water (m.w. = 18.02 g mol–1) to result in exactly 1 L of solution at 25 °C. Assume the density of the solution is that of pure water (dsolution = 1.000 g mL–1). The ebullioscopic constant (Kb) for water is 0.513 °C m–1. The cryoscopic constant (Kf) for water is 1.86 °C m–1. The vapor pressure of pure water is 0.0313 atm. Find the freezing point of the solution(in C to 2 decimal places)
Arterial blood contains about 0.25 g of oxygen per liter at 37°C and standard atmospheric pressure. Under these conditions, the Henry's law constant is kH = 3.7 ×× 10–2 mol/(L • atm), and the mole fraction of O2 in the atmosphere is 0.209. Part1:Calculate the solubility (in M) of O2 in the blood of a climber on Mt. Everest, where Patm = 0.35 atm.___M Part2: Calculate the solubility (in M) of O2 in the blood of a scuba diver at a depth of 100 feet, where Patm = ~3 atm.___M
The Rast method uses camphor (C10H160) as a solvent for determining the molar mass of a compound. When 3.26 g of unknown compoud are dissolved in 85.70 g of camphor (Kf = 40.0 °C/m), the freezing point of the mixture is 170.30 °C; that of pure camphor is 178.40°C. What is the molar mass of unknown compound? Express your answer with 4 decimal places.
Given: Mass of lauric acid (g): 8.000g Mass of benzoic acid (g): 1.027g Freezing temperature of pure lactic acid(°C): 43.3°C Freezing point of the benzoic acid-lauric acid mixture(°C): 39.8°C Question: Calculate molality (m,) in mol/kg, using the formula ΔTf = m × Kf. The Kf value for lauric acid is 3.9°C x kg/mol.
Mm.9.
Ff.94.
mm.32.
At 25 °C the solubility of lead(Il) bromide is 2.70 x 10 mol/L. Calculate the value of Kgp at this temperature. Enter your answer in exponential format using a capital "E (example 1.23E-4) and no units (value 2%).
Please answer.
When 80 mg of an unknown white powder found at a crime scene is dissolved in 1.42 mL of ethand density = 0.789g/mL, normal freezing point -114.6 °C, Kf = 1.99 °C/m), the freezing point is lowere -115.6 °C. Which of the following substances could be responsible for this freezing-point depressio (assume the powder is a nonelectrolyte) Show all the work you used to determine the answer. a) meta-tyramine (C8H₁₁NO: MM = 137.182 g/mol) b) sucrose (C12H22O11: MM = 342.2965 g/mol) c) cocaine (C17H21NO4: MM = 303.353 g/mol) d) fructose (C6H12O6: MM = 180.16 g/mol) e) codeine (C18H21 NO3: MM = 299.364 g/mol) of been uov bluow 10cl doum woh (3
The boiling point of diethyl ether, CH3CH₂OCH₂CH3, is 34.500 °C at 1 atmosphere. Kö(diethyl ether) 2.02 °C/m In a laboratory experiment, students synthesized a new compound and found that when 11.39 grams of the compound were dissolved in 297.6 grams of diethyl ether, the solution began to boil at 34.768 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound ? g/mol
When 98.9 g of glycine (C₂H5NO₂) are dissolved in 900. g of a certain mystery liquid X, the freezing point of the solution is 4.7 °C lower than the freezing point of pure X. On the other hand, when 98.9 g of iron(III) nitrate = (Fe(NO3)3): are dissolved in the same mass of X, the freezing point of the solution is 5.4 °C lower than the freezing point of pure X. Calculate the van't Hoff factor for iron(III) nitrate in X. Be sure your answer has a unit symbol, if necessary, and round your answer to 2 significant digits. i= 0

Recommended textbooks for you

Chemistry

ISBN:

9781305957404

Author:

Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:

Cengage Learning

Chemistry

ISBN:

9781259911156

Author:

Raymond Chang Dr., Jason Overby Professor

Publisher:

McGraw-Hill Education

Principles of Instrumental Analysis

Chemistry

ISBN:

9781305577213

Author:

Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:

Cengage Learning

Chemistry

ISBN:

9781305957404

Author:

Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:

Cengage Learning

Chemistry

ISBN:

9781259911156

Author:

Raymond Chang Dr., Jason Overby Professor

Publisher:

McGraw-Hill Education

Principles of Instrumental Analysis

Chemistry

ISBN:

9781305577213

Author:

Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:

Cengage Learning

Organic Chemistry

Chemistry

ISBN:

9780078021558

Author:

Janice Gorzynski Smith Dr.

Publisher:

McGraw-Hill Education

Chemistry: Principles and Reactions

Chemistry

ISBN:

9781305079373

Author:

William L. Masterton, Cecile N. Hurley

Publisher:

Cengage Learning

Elementary Principles of Chemical Processes, Bind…

Chemistry

ISBN:

9781118431221

Author:

Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard

Publisher:

WILEY

SEE MORE TEXTBOOKS