Recrystallization Post-Assignment

Suppose that you have a 1:1 mixture of compounds that is comprised of compound X and compound Y. You desire pure compound X and are planning a recrystallization to enhance the purity. Which solvent below is optimal for your recrystallization?      Ethanol (boiling point = 78 °C)   Solubility At   0  °C 100  °C Compound X 0.05 g/mL 0.20 g/mL Compound Y 0.02 g/mL 0.40 g/mL           Water (boiling point = 100 °C)   Solubility At   0  °C 100  °C Compound X 0.02 g/mL 0.05 g/mL Compound Y 0.01 g/mL 0.10 g/mL           Methanol (boiling point = 65 °C)   Solubility At   0  °C 65  °C Compound X 0.04 g/mL 0.10 g/mL Compound Y 0.02 g/mL 0.30 g/mL         Acetone (boiling point = 56 °C)   Solubility At   0  °C 56  °C Compound X 0.10 g/mL 0.50 g/mL Compound Y 0.20 g/mL 0.50 g/mL         Ethyl Acetate (boiling point = 77 °C)   Solubility At   0  °C 77  °C Compound X 0.10 g/mL 0.60 g/mL Compound Y 0.30 g/mL 0.60…

The alcohol content of hard liquor is normally given in terms of the “proof,” which is defined as twice the percentage by volume of ethanol (C2H5OH) present. Calculate the number of grams of alcohol present in 1.00 L of 75-proof gin. The density of ethanol is 0.798 g/mL. Round off to 4 sig. figures for all calculations made prior to final answer and the final answer should be in 3 sig. figures

Why is fractional distillation more efficient than simple distillation when purifying liquid mixtures?

A certain liquid X has a normal boiling point of 93.90 °℃ and a boiling point elevation constant K₁ = 1.14 °C-kg-mol¯¹. Calculate the boiling point of a solution made of 40.1g of zinc chloride (ZnCl₂) dissolved in 350. g of X. Round you answer to 4 significant digits. °C x10 X 1 Ś

A student wants to determine how different factors affect the rate of dissolving a solid in water. Trial Size of Particles Rate of Dissolving 1 small 10 sec medium 20 sec 3 large 30 sec What procedures can be performed on trials 2 and 3 so that the rate of dissolving is the same as trail 1? The student can decrease the temperature The student can decrease the pressure The student can increase the pressure The student can increase the temperature

Need help, please.

5. Why does slow distillation result in better separation of two liquids than fast distillation?

Solutes have almost no effect on the boiling & freezing points of a solvent.  True  False

Explain the principle behind vacuum distillation.

2. The table below has IUPAC names and boiling points for four of the organic compounds discussed in the Kahn Academy video on simple and fractional distillation. Draw the structure of each compound, and label the polar and nonpolar groups with the type of attractive force the molecules can use to interact with one another. acetone (2-propanone); boiling point = 56 °C Polar dipoit-dipole dispersion, nonpolar cyclohexane; boiling point = 81 °C 가~ -nonpolar, dispersion ethanol; boiling point = 78 °C Polar, hydrogen (OH) bonding nonpolar acetic acid (ethanoic acid); boiling point = 118 °C E polar, dipole-dipole honpolar, OH 7-polar, hydrogen bonding dispersion Explain the relative boiling points of these compounds in terms of the attractive forces and masses of each molecule.

A chemistry student wishes to extract 2.34 g of compound X from 15 mL of an aqueous mixture. She has two solvents available with the following characteristics: Solvent Solubility of X in 100 mL of solvent Нехane 36.92 Chloroform 28.33 Water 16.52 However, the student only has enough hexane (exactly 10 mL) for one extraction. On the other hand, she has enough chloroform (exactly 20 mL) to perform either 1 extraction with 20 mL or 2 sequential extractions with 10 mL each.

30 20 10 From the procedure 2. Assemble the simple distillation apparatus as generally shown in Figure SD.1 in the lab manual, ensuring that the thermometer bulb is aligned at, or slightly below, the Y in the distillation head. Each ground joint is greased by putting three or four stripes of grease lengthwise around the male joint and pressing the joint firmly into the other without twisting. 3. Attach a water condenser to the distillation head. 4. Remember, water goes in the bottom and out the top. Attach a clamp holder to the end of the drain tube to keep it weighted in the drain. Turn water to a trickle. If it is slowly draining, it is high enough. Begin a low flow of water through the condenser. 5. Place the set up on a heating/stir plate. 6. Turn on the hot plate to start heating the solution. Monitor the temperature and the boiling of the solution throughout the distillation process. 7. Record the temperature of the distillate when the first drops are recovered. 30.0 8. Adjust…

A 1.232-gram sample of copper complex weighed 0.783 g after heating. What is the percent of volatile material in this sample? If the sample contains 17.4% ammonia, what is the percent water in the sample?

B. Simple Distillation SAMPLES °C at which vapors are collected Distillate Water + Acetone 56 Water Pentane + Heptane 37 Toluene + Hexane 69

Part C: Determination of the alcohol content of unknown liquor Stretien Volume (mL) Sample ТИШТИНА 0.00% alcohol 10.0% alcohol 20.0% alcohol 40.0% alcohol 50.0% alcohol Unknown Mass (g) 1o podina ko 9.8919 9.7899 9.600 9 9.420 д % Alcohol content of the liquor 9.2155 9.5089 2VLELA CVOLION: MEAEK EVI OK DRA IVBOKY LOBAN ocen 10.00 10.00 10.00 10.00 10.00 10.00 Density (g/mL) 0.00% alcohol calculation: ися → о 0.99 во 0.99 To Z si doleW 120.00 supinubst sdi na LANG 411 bet [squardas: 0.97 0.94 in oil to notisalarisi 0.92 0.95

A certain liquid X has a normal freezing point of -2.10 °C and a freezing point depression constant -1 K₁=3.79 °C kg-mol . A solution is prepared by dissolving some zinc chloride (ZnCl₂) in 450. g of X. This solution freezes at -5.3 °C. Calculate the mass of ZnCl₂ that was dissolved. Round your answer to 2 significant digits. g x10 X Ś

List these solvent systems in order of increasing polarity 200:1 Ethyl acetate : acetic acid 15:1:1 Ethyl acetate : ethanol : acetic acid 75% Ethyl Acetate / 25% hexanes 50:50:1 Ethyl acetate : hexanes : acetic acid 80:20:1 Ethyl acetate : hexanes : acetic acid

Part C: Determination of the alcohol content of unknown liquor Stretien Volume (mL) Sample ТИШТИНА 0.00% alcohol 10.0% alcohol 20.0% alcohol 40.0% alcohol 50.0% alcohol Unknown Mass (g) 1o podina ko 9.8919 9.7899 9.600 9 9.420 д % Alcohol content of the liquor_ 9.2155 9.5089 2VLELA CVOLION EAEK EVI OK DRA IVBOKY LOBAN ocen 10.00 10.00 10.00 10.00 10.00 10.00 Density (g/mL) 0.00% alcohol calculation: ися → о 0.99 во 0.99 Ano 7 si dotaW 120.00 supirmbest sdi na LANG 411 be: [scpoidas: 0.97 0.94 in oil to notisalarisi 0.92 0.95

A certain liquid X has a normal boiling point of 105.30 °C and a boiling point elevation constant K₁ = 1.74 °C-kg-mol¯¹. Calculate the boiling point of a solution made of 8.59g of ammonium chloride (NHCl) dissolved in 150. g of X. Round you answer to 5 significant digits. пос x10 X

Dynamic equilibrium can be defined as O rate of dissolution rate of dissolving rate of condensing > rate of bubbling rate of dissolution = rate of recrystallization. rate of dissolution > rate of recrystallization.

6. Suppose you have a mixture of water and your 2-bromo-2-methylbutane product in a separatory funnel. Use densities to predict which phase will be the top layer in the funnel. a. 2-bromo-2-methylbutane (organic phase) b. water (aqueous phase) c. there would only be one phase since the substances are miscible

Using recrystallization techniques, a student attempts to purify 0.50 g of compound H. Based on the solubility of H in the chosen solvent at collection temperature, the maximum percent recovery is 82%. The student obtains 0.396 g of purified crystals. What is their percent recovery? Group of answer choices 41% 64% 79% 82% 97% none of these

Rank a series of molecules by expected solubility in water based on polarity and hydrogen bonding. Some slightly soluble compounds are included in this exercise. Rank the organic compounds from most soluble to least soluble. To rank items as equivalent, overlap them. View Available Hint(s) Reset Help Η Η Η Η H H H H ннно Н-С-С — С —С— ОН Н-С-С-С —С -Н Н-С—С—С — С -ОН Η Η Η Η Η Η Η Η Η Η Η нн Η Η Н-С—С— О—С—С — Н нн нн Most soluble Least soluble

A 5.04 g sample of a solid containing Ni is dissolved in 20.0 mL water. A 5.00 mL aliquot of this solution is diluted to 100.0 mL and analyzed in the lab. The analyzed solution was determined to contain 5.53 ppm Ni. Determine the molar concentration of Ni in the 20.0 mL solution. concentration: M Determine the mass, in grams, of Ni in the original sample. mass: g Determine the weight percent of Ni in the sample. weight percent: % * TOOLS x10

What is another factor that can influence fractional distillation’s success other than the number of theoretical plates?