Interpretation:Whether aThiele micro melting-point technique can be used to determine the exact melting point of an unknowncompound or not needs to be determined.
Concept Introduction:The Thiele tube is used to determine the melting point of an unknown compound in quantitative analysis.
It is a laboratory glassware that is heated on an oil bath. The Thiele tube is heated with a small flame. As the boiling point of substance reaches, the heating is stopped and the temperature starts to fall which gives the idea about the boiling point of substance.
For the melting point, the temperature must be checked at which the substance starts melting.
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Experimental Organic Chemistry: A Miniscale & Microscale Approach (Cengage Learning Laboratory Series for Organic Chemistry)
- For measuring concentration of a sucrose solution, a polarimeter with a 15 cm tubing sample was used and observed rotation of 20 degree was measured. For calibration curve, different tubing sample with 23 cm length was used. The calibration curve α = 125C was stablished by using the 23 cm standard solution. Calculate concentration of the sucrose solution in percentage.arrow_forwardAssume the data below was collected for two different sample solutions using the same experimental procedure you carried out. Based on the two lines shown below, which solution (orange data points or blue data points) corresponds to the sample with the higher molar absorptivity? 0.9 y4.771 - 0.0728 0.7 0.6 04 0.3 02 y1414 - 0.0546 R0.99642 0.1 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 02 0.1 [Concentration, M] orange data points (lower line) O blue data points (upper line) Absorbancearrow_forwardMelting Point How will you collect data for this experiment? virtually Melting Point Measurement and Correction Approximate melting point of unknown compound: 85 – 96 °C Select an appropriate melting point standard with a melting point closest to the approximate melting point of your unknown compound. Choose the standard: A. 98 – 100 °C Saved A B. 160 – 162 °C C. 252 - 254 °C Measured absolute melting point of the standard: 96 - 98 °C Measured absolute melting point of the unknown compound: 90 - 94 °C Compare the reported and experimental melting points of the standard to determine if any corrections need be done for your unknown melting point. Correction (°C): 92 - 96 Savedarrow_forward
- In order to obtain accurate data it is important to add hear slowly and steadily when the temperature gets close to the melting point of a sample. Why is necessary?arrow_forwardCalculate the temporary hardness, permanent and total hardness of the sample of water from the following results. Also indicate if the sample is Permanent or Temporary. H=1, C=12, 0=16, N=14, Mg = 24, K = 39, Cl=35.3, Ca= 40,S=32, Na =23 If the sample is Permeant use P Temporary T Neither permeant nor temporary use X Blank 1 Blank 3 Blank 5 Blank 7 Sample M₂CO3 Nacl CaCO3 Ca(NO3)2 CaCl₂ KSO4 Mg(NO3)2 MgCl, MgSO4 Blank 9 Blank 11 Blank 13 Blank 15 Blank 17 Blank 19 Total permanent hardness? Total Temporary hardness? Total Hardness? Mg/1 30.2 12.5 42 55.5 22.8 12 60 32 45 Mg(HCO3)2 38 Molecular weight Hardness 85 58.3 100 164 110.6 135 148 94.6 120 146 Blank 2 Blank 4 Blank 6 Blank 8 Blank 10 Blank 12 Blank 14 Blank 16 Blank 18 Blank 20 Blank 21 Blank 22arrow_forwardDid sublimation aid in the purification of the unknown in Part 3? Justify your answer.arrow_forward
- 3. A pure white crystalline compound was found to melt at 131.5-132.0°C when taken on a melting point apparatus, and on further heating, the liquid was found to start bubbling at ca. 155-160 °C. The capillary containing the melted compound was set aside to cool, and resolidify. When the sample was retried using that same capillary, the sample melted at 120.6-154.5°C, along with some bubbling. What is the cause of the bubbles? Why is the melting point so wide the second time? Explain by stating what you have learned in this laboratory about melting points.arrow_forwardWhy is fractional distillation more efficient than simple distillation when purifying liquid mixtures?arrow_forwardOne method for quantitative determination of the concentration of constituents in a sample analyzed by gas chromatography is the area normalization method. In this method, complete elution of all of the sample constituents is necessary. The area of each peak is then measured and corrected for differences in detector response to the different eluates. This correction is accomplished by dividing the area by an empirically determined correction factor. The concentration of the analyte is found from the ratio of its corrected area to the total corrected area of all peaks. For a chromatogram containing three peaks, the relative areas were found to be 16.4, 45.2, and 30.2 in the order of increasing retention time. Calculate the percentage of each compound if the relative detector responses were 0.60, 0.78, and 0.88, respectivelyarrow_forward
- What is each cycle of a simple distillation called? Theoretical plate Distillate Condensate Fraction Eluentarrow_forwardDescribe principles of separation by capillary isotachophoresis (CI) using a diagramarrow_forwardThe melting point (mp) range of reference compound A is 320-340°C. The mp range of a 1:1 mixture of a sample of A with a sample of unknown compound B is found to be 140-300°C. Do the samples consist of identical compounds? A)Yes, because the mp of the mixture is lower than the mp of pure A. B) Not enough information is given to answer the question C) Yes, because they melt over a broad range. D) No, because the mp of the mixture is lower than the melting point of pure A.arrow_forward
- Macroscale and Microscale Organic ExperimentsChemistryISBN:9781305577190Author:Kenneth L. Williamson, Katherine M. MastersPublisher:Brooks ColeEBK A SMALL SCALE APPROACH TO ORGANIC LChemistryISBN:9781305446021Author:LampmanPublisher:CENGAGE LEARNING - CONSIGNMENT