In some cases Oxygen is also introduced as a reactant carrier to control the characteristics of the film. B. Vapour phase reaction Constituent species in the gaseous phase react in the presence of inert, oxidizing or even some reducing atmosphere to form the desired product. Thus SiO2 films can be produced by the reaction of SiCl4 vapour with carbon dioxide in the pressure of hydrogen gas and this is known as Philips process. The reaction goes in the following way SiCl4 + CO2 + H2 SiO2 + CCl4 + H2 --------------- (3.9) SnO2 films often used as metal oxide resistors can be prepared from SnCl4 vapours in presence of water and HCl vapours at a temperature about 500˚C and the reaction can be represented by the equation SnCl4 + 2H2O + HCl SnO2 + 4HCl + HCl ---------------
RUBISCO catalyses the oxygenation of the first reactant of the Calvin cycle, producing two products: one 3-phosphoglycerate and one phosphoglycolate (Taiz, L & Zeiger, E., 2010; Lambers et al. ; 2008; Christoph P. et al., 2010). The first product is the normal substrate used in the Calvin cycle whereas the second product is unstable and cannot be used in the Calvin cycle. 5.1 The major enzymatic reactions in the photorespiratory pathway 5.1.1 Dephosphorylation of 2-phosphoglycolate Phosphoglycolate produced produce in chloroplast is phosphorylated and this is carried out by phosphoglycolate phosphatase. The resulting product, glycolate is then transported by specific proteins to the peroxisome.
When the refluxing time is 1 h in the case of 4-methylaniline, the yield is 30%, and when it is 4 h in the case of 4-methoxyaniline, the yield is 45%. The yield goes on decreasing in each case when refluxing time is increasingly more than that specified. Their proton NMR spectra show that in each case only one sharp methyl signal is obtained. The 1H NMR spectrum of [ZnL3](ClO4)2.4H2O is shown in Fig. 2.
Applied by Instrument called Chloronome. Use of Bleaching powder and Hypochlorite (a) Commercially available Calcium hypochlorite (HTH) or perchloron (contains 60% to 70% of Cl2 1 kg HTH for 1 million litre of water is required. (b) Bleaching powder (CaOCl2) Contains 30% of Cl2 They raise pH & hence not used these days Use of Chlorine tablet Single tablet of 0.5g is sufficient for 20 litres of water. Use of Chlorine Dioxide Unaffected by pH. (6 to 10) hence advantageous for treating alkaline water with pH 8 to 10 Types of Chlorination Plain Chlorination Only chlorine treatment to raw water ≈ 0.5 mg/L Pre Chlorination Apply Chlorination before filtration.
The HA removal efficiency was less than 50% (Fig. 1a). When the CB dosage was higher than 0.2 mmol/L, considerable amounts of flocs formed. At a CB dosage of 0.3 mmol/L, the residual turbidity was approximately 1.5 NTU after sedimentation, corresponding to 89% of HA removal. The residual HA concentration of the settled water could be controlled within 1.50 mg/L.
This helps to indicate whether or not the reaction follows Markovnikov’s Rule, which states that the electrophile (E+) will add to the carbon involved in a double bond that produces the most stable carbocation. If the rule is followed, the reaction will proceed according to the mechanism in Figure 1. In the silver nitrate test, the alkyl bromide is added to AgNO3. The rate of precipitation with 2° should be faster than the solution with the 1° alkyl halide. In the sodium iodide test, the alkyl halide is added to sodium iodide in acetone.
Liquid phase hydrogenation which is also known as IFP process .2 2. Gas phase hydrogenation of benzene.2 Liquid phase hydrogenation of benzene: IFP process: IFP process takes place entirely in liquid phase in temperature maintained about 2000C and pressure of 4x10^6 Pa absolute in the presence of Nickel catalyst. The purity of cyclohexane obtained is 99.8%. 3 Advantage of liquid phase: 1. Liquid phase is chosen for the hydrogenation of benzene because liquid phase hydrogenation uses low temperature which is less costly.2 2.
It is also known as electron donor. A reducing agent is oxidized, because it loses electrons in the redox reaction. An oxidation-reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between two species. An oxidation-reduction reaction is any chemical reaction in which the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron. Redox reactions are common and vital to some of the basic functions of life, including photosynthesis, respiration, combustion, and corrosion or rusting.
The two line meet at pH 4.5. above this pH value as removal eff was much more for arsenate. It indicates nzvi/ac is superior for removal of as(iii) at diff pH of ground water. Adsorption of arsenate on nzvi/ac decreases from neutral to alkaline media while for arsenate it increases in acidic media and decreases in alkali media. In this case pH of zero point charge obtained at pH 7.4 . at pH <9, arsenate species are H3AsO3 is predominant and in pH range 9-12 H2AsO3- is predominantly available in drinking water.