Vitamin C

Now that pretty much all my friends have left to their respective universities, I've had a lot of time to do the very boring yet nonetheless interesting experiments I've not yet had the time to do. One of these is calculating the emissivity of an aluminum heat sink I have on an amplifier. The heat sink dissipates the heat from two large bipolar junction transistors that are used as the second stage of a two stage class A stereo amplifier. The amplifier is only about 20% efficient, consuming about 50 watts and sending a max of only 5 watts to each of the speakers. As a result, the transistors get quite hot. The heat sink is a square piece of aluminum measuring 12.7 cm x 12.7 cm x .635 cm. Over the course of 1 hour I tracked the temperature given by a digital temperature probe every 30 seconds. The probe was resting between the heat sink and the side of the amplifier. Although this disrupts the ability of the heat sink to dissipate heat ideally, it allows for relatively ...

I used the ~43 grams of Salicylic Acid made in a previous post to synthesize methyl salicylate. Methyl salicylate is the ester that gives wintergreen its distinct flavor and odor. The process is known as a fischer esterification. The procedure is simple, and consists of dissolving the salicylic acid in an excess of anhydrous methanol, and then adding 40ml of concentrated sulfuric acid as a catalyst and refluxing for about two hours. After the reflux, around 50% of the methanol is distilled until the oil methyl salicylate precipitates. The mixture is poured into a separatory funnel and the oil layer is isolated. The oil is then washed with saturated sodium bicarbonate solution twice. The oil, cloudy with methanol and water is then dried using calcium chloride. The oil is totally clear and has a very pleasant refractive index. It has a slight yellow color due to dissolved sulfuric acid and contaminants. Depending on its eventual application I may or may not neutralize the acid. It is no...

I am going to attempt to use a base ester hydrolysis to deacetylate acetyl salicylic acid that I collected from aspirin tablets in an earlier post. The conversion to salicylic acid is only a few steps. First, the acetyl salicylic acid is dissolved in a solution containing about equal mass sodium hydroxide. Then it is left to reflux for half an hour and the solution is combined with hydrochloric acid until the pH reaches 1. The salicylic acid precipitates as the pH decreases and it is important to take the pH as far down as possible. The precipitate is then filtered and washed several times with cold water. I then left the product to dry in the buchner funnel with a vacuum being pulled. To further dry it, I left it in an evaporating dish inside an oven.                              

Nile Red has a very well made video on the extraction of acetylsalicylic acid from aspirin tablets. In it, he begins by breaking apart the tablets and mixing mixing them with acetone, then filters the mixture and rotovapping the acetylsalicylic acid from it. I don't have access to a rotovap, and I found that there are ingredients such as propylene glycol and polyethylene glycol. These compounds are soluble in acetone and subsequently would contaminate the product if they were just left in the solution. My solution is to saturate the acetone with the acetylsalicylic acid, then crash it out by dropping the solution into water. The propylene glycol and PEG are miscible with water so they should come out with washing of the acetylsalicylic acid crystals. After crushing the tablets and mixing them with acetone I crashed the acetylsalicylic acid from the solution by mixing with equal parts water. After letting the solution stand the product crystallized out and I was ready to vacuu...

Hi all, I just received an order of 1 lbs of Copper (2) Sulphate pentahydrate ordered from amazon. I will be attempting to produce schweizer's reagent using the copper sulphate for the purpose of dissolving and precipitating cellulose. One roadblock I've come across is obtaining ammonium hydroxide of a substantially high concentration. After finding the msds of the ammonia I have and browsing some home chemical forums, I found that it only has a concentration of around 3% which would make my reagent very dilute. The actual process for the creation of schweizer's reagent is coming from the youtuber Nile Red who makes many fun and informative videos on extractions, and different organic syntheses. The procedure is as follows, precipitate copper hydroxide by mixing a solution of the copper sulphate and sodium hydroxide, then decant off the remaining solution of sodium sulphate and rinse with fresh water. Then mix in the ammonium hydroxide solution to create a deep blue/pu...