The light extinction method was developed based on the works of Piere Bouger, August Beer, and Johann Heinrich Lambert (1760). Bouger observed for the first time that the light intensity of a candle decreases when it passes trough a transparent medium and appointed the length and the medium property as the main parameter to explain the light extinction. The correlation of absorbance and light path was proposed by Lambert. Finally, Beer concluded that absorbance is also proportional to the…
2. Ezbet El Moraba and Al Manshyia well water treatment plants
2.1. Physicochemical parameters
Comparison between different physico chemical parameters was illustrated in table (6) and figures (15,16,17).
The mean value of residual chlorine in Ezbet El Moraba well water treatment plant was 0.03 mg/L, while that of Al Manshyia well water treatment plant was 0.14 mg/L.
The mean values of turbidity of Ezbet El Moraba and Al Manshyia well water treatment plants were 1.4 NTU and…
4.2 Glass Blowing
Glass blowing is a glass-forming process that encompasses inflating molten glass into a bubble, with the help of a blowpipe. A person who blows glass is called a glassblower or gaffer. A person who manipulates the glass with a torch or other tools is known as a lampworker.
4.2.1 Principle of Glass blowing
Glassblowing utilizes a working property of glass known as inflation. This refers to the expansion of glass by passing a small amount of air into it. The property exists…
1.2. The ideal vapor- compression Refrigeration cycle
Many of the impracticalities related with the reversed Carnot cycle can be removed by vaporizing the refrigerant completely before it is compressed and by replacing the turbine with a throttling devices, such as an expansion valve or capillary tube, The cycle that results is called the ideal vapor compression refrigeration cycle, and is shown schematically and on T-s diagram in Fig 1.2. The vapor-compression refrigeration cycle is the most…
A reaction mixture containing 0.5172g of boric oxide and 1.0167g of acetylacetone was prepared and mixed in a 10 mL beaker. The reaction mixture was heated with occasional stirring for 10 minutes. Next, another mixture containing 1.3321g tributyl borate, 3.0005g of vanillin and 15ml of ethyl acetate was prepared in a 50 mL conical flask. The mixture was mixed and a magnetic stirrer was added to the mixture. The mixture was then stirred on a hot plate for 5 minutes at room temperature. After…
Synthesis of PEG-RAFT agent
The synthesis of the macro PEG -RAFT agent, Chain Transfer Agent (CTA), was performed by esterification method. Briefly, RAFT agent (0.4 g, 1.5 mmol) and dihydroxyl PEG (2g, 0.5 mmol) were dissolved in 35 mL of DCM in a 250 mL round bottom ﬂask equipped with a magnetic stirrer. Then, it was placed in an ice bath (0 ºC); Next, DCC (0.25 g, 1.2 mmol) and DMAP (0.015 g, 0.12 mmol) were added. After 30 min of stirring at 0 °C, the reaction temperature is elevated to room…
The Calorimetric Determination of Enthalpy and Entropy Changes of the Thermal Decomposition of Sodium Sulphate Decahydrate
Sodium sulphate decahydrate thermally decomposes to anhydrous sodium sulphate at 50⁰ C and cools to form anhydrous sodium sulphate. Using Hess's Law the enthalpy and entropy changes of this process can be determined in order to deduce the spontaneity of the reaction. The transition temperature was determined by melting the hydrated crystals at 50⁰ C and allowing…
The steps of synthesis process can be explained in Fig. 1.
The Zn (NO3)2.4H2O (zinc nitrate tetrahydrate) and
Al (NO3)2.9H2O (aluminum nitrate nonahydrate) (Merck)
are used as a precursor. ZnO precursor solution with the
concentration of 0.15 M was made by dissolving 0.89 grams of
powder precursor Zn(NO3)3.4H2O in 40 ml of solvent. Solvent
comprises a mixture of 30 ml deionized water and 10 ml of
ethanol. To speed up the process of dissolution, the mixture
was stirred using a magnetic stirrer…
This experiment was performed to determine the identity of an unknown organic liquid using physical constants: physical state, color, and odor, the solubility classification: water soluble or insoluble, the results of characterization tests: Lucas test, 2,4-Dinitrophenylhydrazine test, Bromine in Methylene Chloride test, and Ferric hydroxamate test, and analyses of spectral data: IR spectrum and HNMR . All testing samples were added to testing tubes for observation. Data was…
In this weeks lab each group is assigned an unknown alcohol and an unknown carboxylic acid for testing. Each group then synthesizes an unknown ester from a Fisher Esterification reaction of the given unknown. Once an ester product is obtained, 1H and 13C NMR, boiling point, and smell testes are run on the final product in order to identify all the given unknowns.
The first step of this week’s lab was to mix 3mL of the unknown alcohol and 6mL of the unknown carboxylic…