Theoritically, as the concentration of sodium alginate increases, the diffusion ability of the substrate into the beads will be decreased. This is because to more cross-linking at higher concentrations with more calcium binding sites. That is the reason why beads at high concentration appear bright white in color. At lowest concentration of sodium alginate, immobilization effectiveness will be higher. However, the gel at lowest concentration cannot withstand wear tear and very fragile.
The chloride ion is more polar since it is above bromine on the periodic table and is more prone to hydrogen bonding due to its smaller size. Chloride ions are worse than bromine ions for nucleophilic attack, because the chloride ions are fully solvated and are not as available to attack. This is why Bromine ion is better nucleophile because is less electronegative and is willing to give up electrons. 3. What is the principal organic by-product of these two reactions?
Rose Bengal-(bis(aminoethyl)ethylene glycol) (2) from Rose Bengal disodium salt (1) The synthesis was done following procedure from . Rose Bengal Na+ salt (915 mg, 0.90 mmol) was dissolved in DMF (2ml) and DIPEA (0.312 ml, 1.80 mmol), HATU (308 mg, 0.81 mmol) were added. After activation for 15 min, the mixture was added to O-Bis-(aminoethyl)ethylene glycol trityl resin (309 mg, 0.31 mmol) preswollen in DMF for 2 hours. The coupling reaction wrapped in aluminum foil was allowed to proceed overnight on a nitrogen bubbler apparatus. The resulting red-burgundy coloured resin was filtered and washed well with DMF.
The average equivalent mass for the acid is 135g/mol H+. 3. The answer obtained in Question #2 is the equivalent mass of the acid rather than the molar mass because the acid could be polyprotic, which would mean the equivalent mass is different from the molar mass since it is depending on moles of H+ per molecule, and there could be multiple moles of H+ ions in one mole of a molecule. 4. The KHP and the acid samples must be dried, because there would still be extra water which would skew the molarity.
Sodium Bicarbonate mixed with Hydrochloric acid. The chemical reaction observed showed that there was fizzing and bubbling, this is evidence that a new gas was being produced. This new gas, CO2 was generated from the reaction. After the fizzing stopped a liquid was leftover leading me to conclude the liquid leftover leading me to conclude the liquid leftover was the NaCl and H2O 4. You found a sample of a solution that has a faint odor resembling vinegar (an acid).
But in laboratory, the cleavage usually occurs in non-aqueous media in presence of a Lewis acid catalyst like Al2O3, Li+, Mg2+ etc. Additionally often elevated temperature and excess of nucleophiles are required. There are a few reports where use of a catalyst has not been necessary [3,4]. For example, aminolysis of epoxide by an -amino acid ester proceeds smoothly in refluxing trifluoroethanol . The same reactions fail in water.
Large molecules in a solution will bypass it since they are too large to fit or adsorb to the pores. On the other hand, smaller molecules will get trapped in the pores, thus leaving the column at a much smaller rate than the larger molecules. In borrelidin, the filtrate was extracted with ethyl acetate. This filtrate then underwent gel filtration chromatography, where the stationary phase here is Sephadex LH-20, a soft gel used to separate proteins, and the mobile phase, also known here as the elution solvent, is methanol. The last step in the traditional purification of borrelidin is reverse phase chromatography.
In a supersaturated solution, the solvent is unable to dissolve into the solution, possible because of temperature or due to the fact that there is too much of the solute. Supersaturated is when the concentration of a solution increases beyond the saturation point. Unsaturated solutions have solute concentrations that are lower than the equilibrium soulbility. For a solution to be unsaturated, it has to contain less solute than its maximum amount. When it comes to making soda, a saturated solution would be needed.
Acids are proton donors in chemical reactions which increase the number of hydrogen ions in a solution while bases are proton acceptors in reactions which reduce the number of hydrogen ions in a solution. Therefore, an acidic solution has more hydrogen ions than a basic solution; and basic solution has more hydroxide ions than an acidic solution. Acid substances taste sour. They have a pH lower than 7 and turns blue litmus paper into red. Meanwhile, bases are slippery and taste bitter.
The clear jar is the control where no copper had precipitated and remains suspended. From the left to right, the sample became more cloudy with smaller clumps of precipitants. Even though the sample with 5 mL of NaOH added appeared to be the clearest of the non-control samples, it was clear because less copper had precipitated out of suspension. Discussion and Conclusion From the experiment, it was seen that an increase in pH caused a greater Cu2+ precipitation. The precipitation process creates solids from compounds that were once dissolved in solution, and these solids must be removed by filtration or sedimentation (Casiday et al 2008).
As seen in the trend of both buffer, once the pH is lower than 3, the slope of dv/dpH increase drastically, showing the decreasing effects of the buffer. On the other hand, in the trend of both buffer on the right side of graph shows when NaOH is added, the change in pH is more drastic once past about pH 5. Although buffer 1 and buffer 2 shows a similar trend, the plot of buffer 1 is above the plot of buffer 2. The reason for this is that buffer 1 is made by an acid and base with an almost equal concentration. This makes buffer 1 a greater buffer compared to buffer 2.