8- Repeat step( 6 ). 9- Wash the ester layer with 6 ml saturated sodium chloride , shake and allow two layers to separate . At this point ,The ester layer should not be cloudy . Again discard lower layer. 10- Transfer the ester layer to a small dry test tube and dry the ester with anhydrous CaCl2 and stir for 10 min.
The column was heated to 40 °C and coupled to a detector PDA-SPD-M20A detecting every 1.2 nm from 190 to 800 nm. The used eluent is a mixture of 85% water acidified to pH = 3 with H3PO4 and 15% nitric acidand the flow rate was set to 1 mL/min. The detection wavelength was set at 222 nm. The identification of intermediates by HPLC analysis was verified by comparing their retention time and the UV/VIS spectra of pure
Formation of ionic bond Activity 3.3 1) Draw diagrams to illustrate the formation of ionic compounds in sodium chloride, magnesium oxide, magnesium chloride, sodium peroxide, and sodium sulphide. The transfer of electrons from one atom to another is called ionic bonding. This type of bonding occurs between metals and non-metals. The compounds formed are called ionic compounds. As stated previously, metals try to lose their outer electrons while non metals look to gain electrons to obtain a full outer shell.
the output gases travels to the scrubber where they are cooled down by spraying distilled water from the top of the column , so the gases rise up due to its light density . By a help of a fan the gases are pulled from the scrubber to the absorber . there is a chemical in the absorber called as monoethanolamine it has a liquid nature. This chemical is used to absorb CO_2 only and according the high density of it it settled down while other gases goes out. The settled mixture at the bottom can be called as rich miya.
We added sodium carbonate until the pH of the mixture was 8. After neutralize, we collected benzocaine by vacuum filtration. We used a Buchner funnel to collect benzocaine. We used three 10 ml of water to wash the product. After the product was dry, we weighed, calculate the percent yield and determined the melting point of the product.
In the second step, the addition of sodium borohydride reduced the imine into another derivative, which was yellowish lime color. The solution turned clear when acids and anhydrides was added, which indicated the precipitate were dissolved. However, after refluxing for a while, yellow precipitates begin to form near the top of the flask. It was assumed that the remaining starting material was concentrated from a decrease volume to reappeared in solution. Nevertheless, this may have been a sign of contamination that will negatively affect the entire reaction.
The comb was then placed into the solution to create the wells. Once the gel had solidified (4-5 minutes) the comb was carefully removed. The solidified gel was then placed into the buffer chamber ensuring that the wells were located closest to the negative terminal. This ensures that the DNA will travel through the gel in the direction of the positive terminal. If the wells are placed closest to the positive terminal it will result in the DNA running off the gel and a failed procedure.
Finally the hexane layer was washed with 100 ml water and then evaporated to dryness with a vacuum rotary evaporator. The concentrated extract was then passed through a chromatographic column (30 cm x 10 mm i.d) containing 2 g florisil (lower) and 1 g sodium sulphate (upper) which is pre wetted with hexane: acetone (1:1). OCPs were eluted with 25 ml hexane: acetone (1:1).The solvent was evaporated using rotary evaporator and final volume was adjusted to 5 ml, which is used for GC analysis. All the sediments were analyzed for HCH and
Dissolve the salt in 60 ml of tap water. Add 30 ml 6 M Hcl and stir the mixture with a glass rod. Add 12 g solid Nacl to the solution and stir the mixture for about 2 minutes. Support a 250 ml separatory funnel on a ring, making sure that the stopcock is closed and that a clean beaker is placed beneath the exit tube. Transfer the aqueous solution from the beaker to the separatory funnel.
Add deionized water to the volumetric flask to the 250ml mark on the volumetric flask. 13. Read the volume from the bottom of the meniscus. 14. Swirl the solution to ensure that the oxalic acid crystals are properly dissolved in the deionised water.
Methanol was filled in a test tube and placed into a water bath to heat up. 12 Drops of the Methanol were then added to each flask until the crude caffeine had completely dissolved. 13. The solution was then filtered and the residue collected in a filter paper. It was left to dry and