Determine the midpoint of the starting and completed melting temperatures. Use those temperatures to graph the melting points of the pure compounds and the mixtures. Table 3. Melting pont analysis Table view List view Table 3. Melting point analysis Start melting temp (°C) Complete melted temp (°C) Midpoint of melting temp range (°C) Pure benzoic acid 80:20 mixture (benzoic acid:mandelic acid) 121 125 123 115.5 113 118 60:40 mixture (benzoic acid:mandelic acid) 104 99 109 40:60 mixture (benzoic 99.5 acid:mandelic acid) 95 104 20:80 mixture (benzoic 109.5 acid:mandelic acid) 107 112 120.5 Pure mandelic acid 118 123 140 120 Chart Title y= 0.5x+73.833 B²=0.9967 100 y=-0.4875x+119.75. R2-0.998 60 80 Axis Title 60 60 40 40 20 -10 10 10 30 30 50 Axis Title 20 70 96 90 110

Determine the midpoint of the starting and completed melting temperatures. Use those temperatures to graph the melting points of the pure compounds and the mixtures. Table 3. Melting pont analysis Table view List view Table 3. Melting point analysis Start melting temp (°C) Complete melted temp (°C) Midpoint of melting temp range (°C) Pure benzoic acid 80:20 mixture (benzoic acid:mandelic acid) 121 125 123 115.5 113 118 60:40 mixture (benzoic acid:mandelic acid) 104 99 109 40:60 mixture (benzoic 99.5 acid:mandelic acid) 95 104 20:80 mixture (benzoic 109.5 acid:mandelic acid) 107 112 120.5 Pure mandelic acid 118 123 140 120 Chart Title y= 0.5x+73.833 B²=0.9967 100 y=-0.4875x+119.75. R2-0.998 60 80 Axis Title 60 60 40 40 20 -10 10 10 30 30 50 Axis Title 20 70 96 90 110

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

In chem lab when creating aspirin, how does a melting point range for pure aspirin compound differ from impure? Explain the meaning of value and range of melting point. How does the meaning of value melting point and range of melting point
Above is a fractional distillation set up. Name five things wrong with the set up.
4. A 100 mL solution was prepared by dissolving 10.00 g of CaSO4 (MW= 136. 14 g/mol) in water. The density of the solution was found to be 1.15 g/ml at 25 C. Find the new boiling and freezing temperature of water in this solution. Answers in 2 decimal places. no need to write the unit. New boiling point = [A] %3D New Freezing point = [B]
What are the functions of the graduated cylinder and distillate in a distillation set-up?
Could the following compound mixtures be separated by simple distillation? Explain why or why not? a. diethyl ether/ 1-butanol (b.p. 34.6 degrees celsius/ 117 degrees celsius) b. water/ethanol (b.p. 100 degrees celsius/ 78 degrees celsius)
A student obtains 0.95 g of crude 9-fluorenone and performs a recrystallization in cyclohexane (13 mL per 1 g crude 9-fluorenone). If the student recovered 0.57 of pure 9-fluorenone, what was the percent recovery of the recrystallization? Report your answer to no decimal places. Your Answer: Answer
Question 4. You are on a field trip with your professor and he asks you to make a fixative solution to collect and preserve specimen. You are told to prepare 200 mL of fixative solution containing 30% formaldehyde (vol/vol), 1X glycerol and 2.5 mM sodium chloride (NaCI). In the field trip van you find a stock of 100% pure formaldehyde (liquid), a 10X glycerol stock (liquid), plenty of water and a stock solution of 5M NaCl. There are also all kinds of pipets, cylinders and beakers to measure volumes. 1. a) provide calculations and describe the process of making the fixative solution?
Compare the percentages of water for each trial? Are they close to one another? Why/why not? trial 1 = 28.6%trial 2 = 29.8%trial 3 = 24.8%trial 4 = 28.8%
A 250 mL solution was prepared by dissolving 10.00 g of Na2CO3 (MW= 105.99 g/mol) in water. The density of the solution was found to be 1.20 g/ml at 25oC. Find the new boiling and freezing temperature of water in this solution. Answers in 2 decimal places. no need to write the unit. New boiling point = New Freezing point =
1. As shown below, a student obtains two quality chromatograms for her distillate and pot samples, containing methanol and cyclohexanol. Match Chromatograms A and B with distillate or pot, and explain your conclusion. Circle your response: Chromatogram A A: Distillate or Pot Explain your answer: t=0 Chromatogram B B: Distillate or Pot
Concerning the following two mixtures, methanol/tetrahydrofuran and chloroform/ethylene glycol, could each mixture be separated using fractional distillation?
A homogeneous mixture consists of 5% methanol, 70% isopropanol, and 25% water. Label these components as solvents or solutes. methanol: [ Select ] isopropanol: [ Select ] water: [ Select ]