Lab 6- manual-Extraction of photosynthetic pigments from plants

You carry out an experiment on the physical properties of 3 organic compounds and observe the following data: Substance Solubility in Water medium Compound A low Compound B high Compound C You know that the 3 organic compounds are an alkene, ketone and alcohol of equal hydrocarbon length. Match the compounds above to their specific organic compound type based upon their solubility. And give a structural reason for the solubility observations that are observed. Substance Identity Reason Compound A Compound B Compound C

3. Corev was synthesizing a chemical in the laboratory. He used different purification techniques to try to obtain a pure compound. The melting point of the pure compound is 65 degrees. When he tested his compound in the lab the melting point he obtained was 62-68 degrees. Is the product he synthesized pure? 4A company was low on copper metal and decided to use some chemical additives just this once to some copper wiring they were installing in a house. How will this impact the conductivity of the wiring?

Which of these types of coprecipitation happens with greater probability when the particle growth of a single crystal happens very quickly, allowing a contaminant to be trapped within a particle?   Mixed crystal formation   Occlusion   Surface adsorption   Mechanical entrapment

Log Koc = 2.36 for the pesticide Carbaryl.  Rainwater percolating down through the soil contains 5 ppb Carbaryl. Organic matter makes up 3% of the soil. Calculate the amount of Carbaryl adsorbed per gram of soil.

Acrylonitrile and water are produced from propene, ammonia, and oxygen in a 2 L vessel by the following reaction: C3H6 + NH3 + O2   →→    CH2CHCN + H2O If 27.6 moles of H2O is produced in 5-min.  What mass of propene  in Kg (kg) is consumed in 30-min. Assume Molar Weight of propene = 42.08 g/mL

A concentration of toxic metals in plant tissue is often found by combusting the material in a furnace and then dissolving the ash in concentrated acid. A 0.5124-gram sample of leaves was combusted to ash and transferred to a 150-mL beaker. A 25-mL portion of concentrated HCl was added and the mixture was heated on a hot plate. Three 5-mL portions of concentration HCl were added over approximately 10 minutes with continued heating in between additions. The resulting mixture was cooled to room temperature and filtered into a 50-mL volumetric flask, which was brought to volume using distilled water and mixed well. From this stock solution, a 10-mL portion was pipetted into a clean 50-mL volumetric flask, brought to volume with distilled water, and mixed. This final solution was analyzed and found to contain 12.1 ppm lead. What are the mass percent of lead in the original plant tissue?

In this station, you will find a sample of table salt; the chemical formula of table salt is NaCl. Using the balance, weigh out 6.00 g of NaCl and dissolve in 50 mL of deionized (d.i.) water. Once com-pletely dissolved, add additional d.i. water to make the final volume of solution 100.0 mL. What is the mass percent NaCl in the solution? What is the molarity of the solution

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Hydroxyapatite, Ca₁0 (PO4) 6 (OH)2, has a solubility constant of Ksp = 2.34 x 10-59, and dissociates according to Ca10 (PO4)(OH)2(s) = 10 Ca²+(aq) + 6 PO¾-¯(aq) + 2 OH(aq) Solid hydroxyapatite is dissolved in water to form a saturated solution. What is the concentration of Ca²+ in this solution if [OH] is fixed at 3.60 × 10-4 M? [Ca2+] = M

Z = [2(σP)/kT][8RT/pi(M)]1/2 2A. Based on the kinetic theory of gases, collision frequency is related to temperature, pressure and molecular cross section. Explain conceptually and based on the equation how the collision frequency is related to pressure.  2B. How does collision frequency relate to temperature. 2C. Sketch a plot of the relationship between collision frequency and temperature. Label your axes.

The solubility of Fe(OH)2 in water at 25 °C is measured to be 5.2 × 10¯ Round your answer to 2 significant digits. 4 g 2. Use this information to calculate Ksp for Fe(OH)2. 日 ☐ x10 ☑

Given the following data/observations for experiment #43B [39B]: a. the mass of Benzyltriphenylphosphonium Chloride (BTPC)(limiting reactant) used was 0.486g. b. the observed melting point of the purified product was 145-149 °C. c. the mass of the purified product was 0.217 g. Calculate the theoretical and the percent yield of the purified product from the above data (show all appropriate calculations and units). Comment on the % yield and the purity of the purified product (included any appropriate errors to explain the results).

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A group of third-year students, who had been growing chilli peppers at home, decided to bring samples to their Pharmacology practical where they would be measuring capsaicin, to determine which of them had grown the hottest peppers. The three students ground a sample of their peppers in 100 µl of distilled water, centrifuged the solution and then transferred the supernatant into a collection tube. One student used 70 % ethanol from a wash bottle on their bench instead of using distilled water as the extraction fluid. Samples of the collected supernatants were added to a 96 well test plate along with a range of serially diluted capsaicin standards. The students used a FlexStation which automatically added 20 µl aliquots of each supernatant onto separate wells containing 80 µl of cultured cells, which had been transfected with the capsaicin sensitive TRPV1 ion channel and preloaded with the ratiometric calcium indicator dye FURA-2 prior to the class. The FlexStation was programmed to…

Data Sheet 4 ble gives the recommended mass of salt to dissolve in each of the four test tubes. Show a sample calculation for the solubility of KNO, using your actual mass from tube #1. Complete your graph on the back of this sheet. Solution # Recommended mass KNO3 Actual mass of KNO, (g per 5 mL H₂O) Solubility & KNO, 100 g H₂O Saturation temperature (°C) (g) 1 2.0 51.3 2.1971 2 62.5 4.0 11.1568 3 72.7 6.0 6.0112 83.6 4 8.0 806 Sample Solubility Calculation: Questions 1. According to your data, how does the solubility of KNO, change with increasing temperature? Does this indicate an endothermic or exothermic dissolving process? Explain. 2. Using your graph, indicate if each of these solutions would be saturated or unsaturated: a) 110 g of KNO3 in 100 g of water at 40 °C b) 60 g of KNO3 in 100 g of water at 70 °C c) 140 g of KNO3 in 100 g of water at 60 °C 3. According to your graph, what mass of KNO3 will dissolve in 100 g of water at 30 °C?

The Ksp value for bismuth iodide, Bil3, is 7.71 x 10-1⁹ at 25°C. Calculate the concentration of iodide at 25°C. Round to two non-zero decimal places. Leave in standard notation if possible.

In any manufacturing process, reaction monitoring ensures that a chemical reaction proceeds as expected. Table 1 shows the monitoring data for the formation of chlorohexane, collected using a technique called gas chromatography. Note that the concentrations of the chlorohexane solutions are given in millimoles per litre (mmol l–1). The abbreviation mM (millimolar) is frequently used. Plot a graph of the data in Table 1. The graph should be drawn on graph paper or use fine grid if it’s drawn on Excel. Elapsed Time/Hours  Concentration of Chlorohexane/mM 0 0 2 40 4 65 6 80 8 90 10 95 12 99

Q1. Give three criteria for a good recrystallization solvent. Q2. You want to purify 10 grams of benzoic acid that has been contaminated with 0.2 g of salicylic acid. You are given the following data: Solubility in water at 20 °C Solubility at 100 °C (g/10 ml) Compound (g/10 ml) Benzoic Acid 0.029 0.680 Salicylic Acid 0.680 0.029 0.22 6.67 a) What volume of Boiling water is needed to dissolve the 10 g of benzoic acid? (show calculations) b) How much benzoic acid will crystallize after cooling to 20 °C (show calculations) c) Will any salicylic acid crystals form? Why or why not? (show calculations/ reason for answer) d) What is the maximum amount of benzoic acid that could be recovered in the first crop of this recrystallization? (Show calculations) e) How can you prove the purity and identity of the purified Benzoic acid?

Ksp = 6.7 x 10-³1 for Cr(OH)3 at 25 °C, what is the molar concentration of Cr³+ at 25 °C? M (example: type in 3.4E-5 for 3.4x10-5). Please pay attention to the number of sig. figs. in your answer. The molar concentration of OH is

3. A sealed glass vial is prepared with 4 mL of air and 36 mL of water. Trichloroethylene (TCE) is added to the water to create an initial aqueous phase concentration of 100 ppb (a) (b) After the system equilibrates, what will the concentration of TCE be in the aqueous phase (in µg/L)? Determine the % mass partitioning of TCE between the water and the air when equilibrium is established. (c) If a quantity of TCE is accidentally spilled into a well-mixed river, where would you expect most of the TCE to end up in the short term - in the air or in the water? Explain.

. These resins are organic polymeric networks that contain functional groups that are permanently attached to the resin. One such functional group is sulfonic acid, -SO3H. When placed in water, the resin (being a large organic molecule) will not dissolve. However, the ionic functional groups become hydrated and the resin will swell as it takes up waters of hydration. The resin may then be thought of as a solid solution mixture with the functional groups being "dissolved" but the polymer remaining as a solid. The hydronium ion (H3O+) associated with acidic functional groups like sulfonic acid will dissociate just as it would if the acid were free of the resin. If other cations such as Cu2+ or Na+ are added to the resin, an ion-exchange reaction can occur:  . Note that one H+ is released for each positive charge bound to the resin.  Since the resin exchanges a hydrogen ion for a sodium ion in this reaction, sulfonic acid resins are called cation-exchange resins. Equilibrium constants may…

4 What will be the ideal precipitating agent in gravimetric analysis? Select one: O React to all elements in Alkaline metals, Alkaline earth metals, and Halogens. O Produce a precipitate that is sparingly soluble. React only to the constituents of the atmosphere. O Produce a precipitate of unknown chemical composition after it is ignited.

Consider the reaction below and answer the question below the reaction. A student performed a synthesis of ethyl 4-aminobenzoate (C) as shown in the reaction above. The student added 1.20 g of 4-aminobenzoic acid and 12.0 mL of ethanol together in the presence of sulfuric acid. The reaction mixture was heated to reflux for a period of 45 minutes. H₂N OH 4-aminobenzoic acid MM 137.14 g/m ol A + CH3CH₂OH ethanol MM 46.10 g/mol B ethyl 4-aminobenzoate ethanol H+ 4-aminobenzoic acid benzocaine none of the above H₂N OCH₂CH3 + H₂O Identify the limiting reagent of this reaction. Hint: the density of ethanol is 0.789 g/mL. ethyl 4-aminobenzoate MM 165.19 g/mol с

Consider the reaction below and answer the question below the reaction. A student performed a synthesis of ethyl 4-aminobenzoate (C) as shown in the reaction above. The student added 1.20 g of 4-aminobenzoic acid and 12.0 mL of ethanol together in the presence of sulfuric acid. The reaction mixture was heated to reflux for a period of 45 minutes. H₂N OH 4-aminobenzoic acid MM 137.14 g/m ol A 77.7% 56.1 % 128 % 72.2 % + CH3CH₂OH ethanol MM 46.10 g/mol H+ H₂N OCH₂CH3 + H₂O ethyl 4-aminobenzoate MM 165.19 g/mol C B Let's assume the theoretical yield of the reaction is 7.22 g and the student produced 5.61 g of ethyl 4-aminobenzoate. What is the percent yield of the reaction?

Consider the reaction below and answer the question below the reaction. A student performed a synthesis of ethyl 4-aminobenzoate (C) as shown in the reaction above. The student added 1.20 g of 4-aminobenzoic acid and 12.0 mL of ethanol together in the presence of sulfuric acid. The reaction mixture was heated to reflux for a period of 45 minutes. H₂N OH 4-aminobenzoic acid MM 137.14 g/m ol 2.44 g 1.21 g 3.24 g 1.45 g + CH3CH₂OH ethanol MM 46.10 g/mol B H+ H₂N OCH₂CH3 + H₂O ethyl 4-aminobenzoate MM 165.19 g/mol A с What is the theoretical yield for the reaction?

The following data was obtained in NASA chemical lab.Temperature (C) Solubility (x 10-21)10 1715 2120 3825 4130 4935 5340 5945 6950 7855 8660 95 Find: the equation Solubility [x10-21] = f(Temperature [K]). Provide the graph withcorresponding labels.