The substitution reaction was successful but not fully effective. 19. If the data was inconclusive, then comparing various compounds and the unknown based on physical characteristics would be the first step, titrations would also be a good method. 20. To get a better yield, redoing the experiment would require careful attention in the recrystallization steps: amount of solvent used, how hot solvent is, if the mixture cools to room temperature before placing it in an ice
Caffeine is more soluble in dichloromethane (14g/100g) than in water (2g/100g). Caffeine will dissolve in the dichloromethane phase while tannins salts remain in the aqueous phase. Addition of sodium sulphate will act as a drying agent and evaporation of the dichloromethane solution would yield pure caffeine which is white in
The Hydrolysis reaction included an acidic environment and an acidic catalyst to make the reaction occur faster and initiate the reaction as well. The acidic environment is required in order to add the hydrogen and oxygen onto the carbonyl groups in the final product. Dicarboxylic acid is not very soluble in water/acetone which ultimately resulted in larger yield of product. 2.
In this experiment, extraction was used as a separation technique to separate the acid, base, and neutral compounds. In extraction, two immiscible solvents with different polarities are used to dissolve and separate different solute components, so they form two distinct liquid layers. In this experiment, ethyl acetate, an organic solvent, and an aqueous solution, were used as the two immiscible solvents. The extraction solvent must be capable of dissolving one of the mixture components, without irreversibly reacting with it. While initially it seems as though the organic acid, base, and neutral compounds would never pass into the aqueous layer, the conjugate acid and base of the organic base and acid respectively are soluble in water.
Although it was hypothesized that the corn syrup would also contain starch, conducted research helped to clarify why this substance was void of starch. First of all, it was hypothesized that whipping cream would not contain starch, and this was confirmed when drops of an iodine solution was added to the test tube. No evidence of starch was observed, but there was a colour change from a white liquid to a yellow hue that stayed at the bottom of the test tube. However, the whipping cream simply took on the colour of the iodine solution, so there was no change that occurred that could have proved a chemical reaction. The reason why whipping cream does not contain starch is due to the fact that starch is found in plants.
In the experiment 1 of intermolecular forces via evaporation, groups were challenged to gain a better understanding of the molecular forces in alkanes and alcohols while also exploring the impact of molar mass on intermolecular forces. Before starting, it must be understood that evaporation is an endothermic process. Substances with weak intermolecular forces will experience a greater temperature drop. Strong intermolecular forces will not experience a great temperature change. Because of the key statements listed, the group predicted that alcohols would experience little temperature change due to the strong intermolecular forces within them.
Then, I came up with a great idea. Maybe the water was supposed to be room temperature and not refrigerated. So, I tried one last time, and ended up with the results going my way. The boiled water finally froze before its cooler counterpart. I ended up with results that supported my hypothesis.
Then, it is air dried and followed by fixing it with flame from Bunsen burner. After fixing the smear, it must be stained using Gram staining solution, firstly crystal violet solution was flood onto it, and allowed for 1 minute, then wash off with tap water. Then, flood the slide with iodine solution for 1 minute and wash it off with tap water again. The formation of a dye-iodine complex will occur in the cytoplasm. Then, it was flooded with ethanol and washed immediately.
The base and acid reacts with each other producing water in the process. This the main way the stomach can be protected from being auto-digesting or digesting itself. ("How does your stomach keep from digesting itself? | HowStuffWorks," n.d.) The mucous doesn’t get digested as it secrets the hydrochloric acid because the pH within the parietal cells remain neutral.
Water leaking through the concrete can carry dissolved salts that get deposited on the wall surface after the water has evaporated. Unlike white mold, the salt itself is harmless and is readily cleaned off. However, simply removing efflorescence does not solve the underlying problem which is the water leakage through the wall. The efflorescence will simply return over time as more leakage occurs, and as mentioned previously, the leakage can cause other serious problems.
Purpose This experiment is to determine the concentration of the solute copper sulfate pentahydrate, and the unknown solution, by passing different wavelengths of light through each solution. Procedure Weigh out approximately 5g of copper sulfate pentahydrate. Record the mass and place the solute into a 50 mL volumetric flask. Fill half of the flask with distilled water, add the stopper for the flask, and lightly shake the flask, until the copper sulfate pentahydrate fully dissolved.