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Activated and Nonactivated Date Pits Adsorbents for the Removal of Copper(II) and Cadmium(II) from Aqueous Solutions
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The present study aims to investigate the adsorption behavior of Cu(II) and ...

The present study aims to investigate the adsorption behavior of Cu(II) and Cd(II) ions from wastewater onto low-cost adsorbents either raw date pits (RDP), cheap agricultural and nontoxic materials, or chemically activated carbon (ADP) prepared by modified date pits using phosphoric acid. A series of experiments were conducted in a batch system to evaluate the effect of system variables. The adsorption process is affected by various parameters such as solution pH, contact time, initial concentrations of metals, and adsorbent dose. The optimum pH required for maximum adsorption was found to be 5.8±0.5. The experimental data were tested using Langmuir, Freundlich, Dubinin-Radushkevich (D-R) isotherm equations. It was observed that the adsorption capacity of date pits increased after treatment with phosphoric acid. The maximum uptake capacities (Qm) were 7.40 and 33.44 mg copper(II) per gram of RDP and ADP. respectively, while 6.02 and 17.24 mg cadmium(II) per gram of RDP and ADP. .

Subject:
Life Science
Material Type:
Case Study
Provider:
King Khalid University
SHMS
Provider Set:
Open Author Resources
Author:
إيناس عبد السميع أحمد
Date created
17-شعبان-1438
Synthesis of tetraamminecopper(II) sulfate monohydrate
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Synthesis of tetraamminecopper(II) sulfate monohydrateThe reaction of ammonia with the copper(II) sulfate ...

Synthesis of tetraamminecopper(II) sulfate monohydrateThe reaction of ammonia with the copper(II) sulfate pentahydrate is a two-step process. In the first step, solid copper (II) hydroxide is formed which is light blue in color. The Cu(OH)2(s) dissolves as additional quantities of ammonia are added in the second step to form the dark blue [Cu(NH3)4]2+ complex. The equations for the process are belowThe copper(II) ammonia complex is water-soluble. In order to precipitate and isolate the final product, you need to decrease the solubility of the ionic compound.  A convenient way of doing this is to add a large amount of ethanol, CH3CH2OH, to the aqueous solution.  Ethanol is much less polar than water, and as the amount of ethanol in the mixture increases, the solubility of ionic compounds decreases.  After the addition of ethanol, your coordination compound will appear as a crystalline solid.  The synthesis procedure ends with filtration, rinsing, and drying of the product. Procedure 1.   Weigh out 2.5 g of copper(II) sulfate pentahydrate (CuSO4 • 5H2O). Place the CuSO4 • 5H2O into a 150 mL beaker and record the exact weight of the solid in your lab notebook. 2.   Add 10- 15 mL of distilled water to the weighted CuSO4 • 5H2O and stir to dissolve the solid. Note: If the solid does not dissolve completely, gently heat the beaker by placing it on a wire gauze above a Bunsen Burner in a hood. Do not heat the solution to boiling. Be sure not to burn the solid onto the bottom of the beaker. Stir often to prevent this. If you have heated the sample, allow it to cool to room temperature by placing it in an ice bath (using ice and tap water) before going on to the next step. 3.    In the fume hood, slowly, with stirring, add 1.5 ml of 15.0 M ammonia (NH3) needed to convert all of your CuSO4 • 5H2O to [Cu(NH3)4]SO4•H2O. You may measure the NH3 with a graduated cylinder. The large excess of NH3 is needed to ensure that the complete reaction occurs. Initially as the NH3 is added, you will see the light blue precipitate of Cu(OH)2 form (see reaction 1 in the Background section).  It should dissolve when you have added all of the NH3. 4.  To decrease the solubility of the tetraamminecopper(II) complex, add approximately 25 ml of ethanol with stirring. The deep blue precipitate of [Cu(NH3)4]SO4•H2O should form. 5.   Place the reaction beaker in a 400 ml beaker of ice water and allow it to stand for 10 minutes so that crystals settle out. * While waiting for your crystals to settle: prepare 20 mL of a solution by combining 10 mL each of concentrated (15.0 M) ammonia and 95% ethanol. Cool this solution in a larger beaker of ice water 6.   Filter your sample.    7.   Use small portions of your cooled ammonia/ethanol mixture to transfer any remaining crystals from the beaker to the funnel. 8.   When your product appears to be dry, transfer your product along with the filter paper into the weight boat. 9.   Allow the precipitate to air dry until the next lab period by carefully placing it into your lab drawer. 10.At the start of the next lab period, weigh the dried precipitate in your lab notebook. 11.Calculate your percent yield. Recall that % yield = actual yield / theoretical yield x 10 

Subject:
Applied Science
Chemistry
Material Type:
Module
Provider:
Prince Sattam Bin Abdulaziz University
Author:
Safa'a Faris
Date created
12-محرم-1440