You need to purify 0.8 grams of an impure sample of trans-cinnamic acid. After the purification is completed you isolate 0.57 grams of trans-cinnamic acid and record a melting point range of 129-132 °C. Cinnamic Acid has a solubility in ethanol of 13.9 g/100 ml at 10 0C and a solubility in water of 0.055 g/100 ml at 25 °C. (a) Explain why the recrystallization of trans-cinnamic acid must use a mixed solvent system. Please explain why the sample couldn't be successful recrystallized in ethanol alone. Calculations should be used to support your answer. (b) Calculate the % recovery and the % error for the melting point.

You need to purify 0.8 grams of an impure sample of trans-cinnamic acid. After the purification is completed you isolate 0.57 grams of trans-cinnamic acid and record a melting point range of 129-132 °C. Cinnamic Acid has a solubility in ethanol of 13.9 g/100 ml at 10 0C and a solubility in water of 0.055 g/100 ml at 25 °C. (a) Explain why the recrystallization of trans-cinnamic acid must use a mixed solvent system. Please explain why the sample couldn't be successful recrystallized in ethanol alone. Calculations should be used to support your answer. (b) Calculate the % recovery and the % error for the melting point.

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

(1) GUIDE:- Substituted working formula - From the general formula, directly present your answer with substituted values already - Format: "F=_+_-_" (examples: F=2+1+1 , F=1+2+2 ... ) - Spaces and other formats will invalidate your answer - Degrees of freedom - Multiple choice, each item is equivalent to one ANSWER THIS QUESTIONS 1a. What is the number of components for the formulation: "Beeswax + Glycerin + Methyl paraben"? CHOICES: A. ONE, B.ZERO, C.TRHEE, D. TWO 1b. Present your working formula for the formulation: "Beeswax + Glycerin + Methyl paraben" 1c. What is the degrees of freedom for the formulation: "Beeswax + Glycerin + Methyl paraben"? CHOICES: A. ONE, B.ZERO, C.TRHEE, D. TWO
Cis-3-hexene and trans-3-hexene can be separated using GC. Explain why these two compounds can be separated by GC and not by fractional distillation.
which of the following statements regarding purification by recrystallization is false? i. activated charcoal removes insoluble impurities. ii. water is the best recrystallization solvent for organic compounds. iii. slow cooling permits the exclusion of the solvent from the recrystallized solid. a. i, ii, and iii b. i and ii c. i only d. ii and iii
An organic chemistry laboratory Extraction; the extraction of crude naphtalene- benzoic acid mixture. Naphthalene is a suspect carcinogen and is toxic to aquatic life. Find an alternative pair of molecules that adhere better to the principles of green chemistry and can be separated by extraction using green' solvents. (kindly answer fully)
According to the USP, the percentage purity of ascorbic acid in tablets must be 90.0% to 110.0%. The amount of pure ascorbic acid determined after the assay procedure was 0.3226 g. If the weight of the sample used was 0.4529 g and the average weight of five 500-mg tablets was 0.6185, the sample conforms to the USP specifications. True False
Arrange the following steps in the correct order. I. Prepare the separatory funnel. II. Mix and release pressure. III. Add the solution to be extracted and add the extracting solvent. IV. Collect the organic layer. a. I, II, III, and IV b. I, III, IV, II c. I, III, II, IV d. IV, II, I, III
for the following, should i use fractional or simple distillation? separation of 1-butanol (Tb = 116 oC) from ethanol (Tb = 78 oC).?
1. Calculate the percent by volume of acetic acid by fermentation. Assumptions: No volume changed during fermentation and conversion efficiency is 85%. Overall chemical reaction facilitated by Acetobacter aceti:C2H5OH + O2 = CH3COOH + H2OGiven: Volume of 6% C2H5OH = 3 LMolar mass of C2H5OH = 46.07 g/molMolar mass of CH3COOH = 60.06 g/molDensity of C2H5OH = 0.789 g/mLDensity of CH3COOH = 1.05 g/mL
why is fractional distillation a better method of separating 1-chlorobutane and toluene than simple distillation
You are performing a transesterification and need to get your reagents ready. You are starting with 28.60 grams of your triglyceride which has a molecular weight of 927.48 g mol-1. a) How many moles of triglyceride do you have? b) How many grams of methanol will you need if the ratio of triglyceride to methanol is 1:8 in your reaction? Ensure you report to the correct number of significant figures for both and show your working.
Given the following statements, which would be the ideal solvent to use for recrystallization of this compound? Why? Compound X is soluble in both cold ethyl acetate and hot ethyl acetate. Compound X is insoluble in cold benzene but soluble in hot benzene. Compound X is insoluble in both cold hexanes and hot hexanes. Compound X is insoluble in cold ethanol but soluble in hot ethanol.
We want to extract terpenoids from an aqueous sample by continuous liquid-liquid extraction. Which of the following solvents is not suitable for this purpose? Why? Propanone (acetone), dichloromethane, heptane.