Faculty of Agriculture‚ AL-Azhar University‚ Cairo‚ Egypt Abstract: This work aimed to evaluate the efficiency of different organic solvents such as‚ methanol‚ ethanol‚ dichloromethane‚ acetone‚ hexane and ethyl acetate for extraction of ( flavonoids and polyphenolic compounds(TFC and TPC respectively) from the orange peel. Also‚ the effect of these solvents on the yield percentage‚ chelating activity‚ antioxidant/radical scavenging capacity and reducing power ability of the produced extracts
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system at 220". We had independently discovered a simpler and more general method for preparing compounds of this type which involves heating chromium hexacarbonyl under reflux in an excess of the aromatic compound or with a molar quantity in an inert solvent. Shortly after our preliminary communication‚2 Natta and his co-workers also described the direct preparation of several of these compounds‚ but used a pressurised system (with intermittent release of carbon monoxide) and higher temperatures (200-235")
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measured‚ the molar mass of an unknown substance can be found. Pre-Lab Questions: 1. a. Determine the freezing point depression 53.02 – 50.78 = 2.24 °C b. Calculate the molar mass of the unknown substance 7.1 °C/m X 2.04 g (solute) X 24.8 g (solvent) X 2.24 °C = 260.0 g molar mass = 260. g 2. What are colligative properties? Colligative properties are properties of a solution that change when the condition of the solution changes. II. PROCEDURE Part B 1. Set up a Bunsen Burner
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has a melting point around 135°C and a pure salicylic acid has 158 °C. TLC is used to separate compounds based on affinity for stationary phase or mobile phase. In TLC‚ the solvent went up at different rates. The retention factor (Rf) of a component can then be measured by dividing the distance that was traveled by the solvent front distance.By doing this experiment‚ the number of moles and grams of salicylic acid and acetic anhydride can be answered. Methods/ Material: Capillary tube TLC Plates
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points of both part a and part b samples were fairly close to the melting point of my pure sample so I would conclude that it was quite pure. 2. Suppose you were performing a recrystallization and you had just added the optimal amount of boiling solvent to dissolve your impure solid…but then you a squirrel ran by and you decided to chase it. When you got refocused and returned to your experiment‚ you realized that you’d left your Erlenmeyer flask containing your recrystallization solution on the
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dispensed into the previously weighed watch glass. The previous steps were then repeated two more times. The watch glass with the decantate was placed to the back of the mini hood so the solvent could evaporate. After half of the solvent was evaporated‚ the watch glass was then moved to the drying oven. Once the solvent was completely evaporated and cooled‚ it was weighed and recorded.
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Experiment 1: Mixtures Aim: To develop an understanding of different types of mixtures including solutions and to examine the different solubilities of some solutes in two solvents: water and ethanol Procedure: Refer to Experiments Book Pg 13 Results: Part A- Mixture Observations Classifications 1 100% Orange Juice There were suspended pulp in the juice Heterogeneous Mixture 2 100% Apple Juice Clear solution Homogeneous Mixture 3 Solder Uniform mixture Homogeneous Mixture 4 Fruit Cake Chunks
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Also‚ the nature of the solvent can affect which substitution reaction will occur. Polar protic solvents typically favor SN1 reactions. This is because the SN1 mechanism is carried out in two steps and the polar protic solvent produces both a cation and an anion which are capable of stabilizing the charges on the ions formed during the reaction. Because an SN2 reaction occurs in one step‚ this is unfavorable; however‚ the SN2 reactions tend to favor polar aprotic solvents. Another factor affecting
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Tessa Landauer Chemistry 0340 Qualitative Analysis Shaopeng Zhang January 26‚ 2015 I submit this laboratory report as an original document. I assert that all ideas and discussion of data contained herein is my own work unless otherwise referenced. Tessa Landauer Abstract The goal of the experiment was to isolate and purify the unknown D liquid and solid by using its acidic and basic characteristics in a chemically active extraction then to identify the unknowns by analyzing the physical properties
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Extraction and analysis of two compounds from unknown solution C ABSTRACT Liquid C and solid C were both extracted from unknown solution by first using chemically active liquid-liquid extract‚ followed by vacuum filtration. Liquid C and solid C were then purified with the use of simple distillation and recrystallization respectively. Through the process of recrystallization‚ the percentage purity of solid C was found to be 6.01%. The melting point range of purified solid C was 117.0 – 119
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