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Mystical view over Ljubljana from Golovec Hill

Mystical alternative view over Ljubljana, Slovenia; on a hill part of Golovec overlooking the city's south part
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Chemistry exercise: mass needed to prepare a solution

One of the most easy exercises in chemistry is calculating concentrations of solutions. However, for a lot of starting students or people new in the field, it remains a hassle to carry out such exercise. Let's say we want to prepare a 0,250 M aqueous solution of calcium chloride (CaCl2). CaCl2 is a white powder at room temperature. It dissolves readily in water. The exercise is as follows: What mass of CaCl2 is required to prepare a 300,0 mL of a 0,250 M solution? (Molecular mass of CaCl2 = 110,98 g/mol) Approach this step by step. First, deduct what is expected. 1. We need to calculate the amount of mass needed. Mass is in gram (g). The solution has a concentration of 0,250 M. This means we want a concentration of 0,250 Molar or = mol/liter. 2. 0,250 mol/liter. But we do not want 1 liter, we want 300 milliliter, or 0,3 liter. Calculate the amount of mol we need: 0,250 mol/liter to 300 milliter, I calculate it as follows: 0,250 mol divide by 1000 (1 liter = 1000 mil

Logarska Dolina, Slovenija // Logar Valley, Slovenia

In 2017 I spent 3 months in Slovenia for a thesis exchange. One of the most beautiful sites I visited is the Logar Valley, or as they call it in Slovenija: Logarska Dolina. One of the downsides is that it's hard to reach when you stay in Ljubljana. I suggest to rent a car or go there by bus and spend the night in the national park (which I hope to do someday). A typical scenery picture I took:

Painkillers: brand names for paracetamol (= acetaminophen) in foreign countries

Do you ever need a medication when in a foreign country, but in this country the medication you need is not available under a certain name? It's useful to know the active compound of the medication! In this case, I will present to you a list of brand names which contain paracetamol (= acetaminophen) throughout the world. When you are in the local pharmacy, ask about the active compound ("paracetamol" or "acetaminophen") and they will know immediately what you mean! If you talk about a brand from your own country it can take a while until the pharmacist knows what you mean. Useful : in almost all countries, generic brands are available, usually under the name of the active compound, so just ask for "paracetamol" or "acetaminophen" if you would like the cheapest product. Paracetamol = Acetaminophen EUROPE Austria: Ben-u-ron, Mexalen Belgium: Algostase, Dafalgan Croatia: Daleron, Lekadol, Plicet Czech Republic/Czechia: Paralen

How to use: Spiriva Handihaler®

Spiriva Handihaler® consists of the anticholinergic drug tiotropiumbromide. This medicin is used in the treatment of chronic obstructive pulmonary diseases, most often abbreviated as COPD. Pharmacology : tiotropiumbromide is a long-acting anticholinergic drug. It blocks the muscarin receptor. This way, the neurotransmitter acetylcholine will not be able to bind on this receptor. The result is a relaxation of the bronchialic muscle tissue. Always use this medication as your doctor/pharmacist advises you. The most commonly used therapy is the inhalation of one capsule a day, on the same hour each day. How to use the Handihaler : Step 1 : It may sound logical, but open the cap and the mouth piece. Step 2 : Gently take a Spiriva capsule. Place it in the open space. Close it off with the mouth piece until you hear a soft click. Press the green button FULLY on the side only once. By pressing this button, the capsule will be "pierced", creating small openings in the cap

Hydrolysis of carboxylate to carboxylic acid

Example of a hydrolysis reaction from carboxylate to carboxylic acid, drawn by myself. The reaction shown is an example of a common hydrolysis reaction used in organic chemistry.  The ester compound on the left (carboxylate moiety), is usually dissolved in 1,4-dioxane. Then, NaOH aqueous solution is added. Conditions are dependent of the type of compound.  Several conditions can be used: - 80 °C, 2 M NaOH, if compound is extremely stable, these are harsh conditions. - 80 °C, 1 M NaOH  - 60 °C, 2 M NaOH  - Room temperature (RT), 2 M NaOH  - RT, 1 M NaOH If the compound is susceptible to degradation or is unstable, use room temperature and a low molarity of NaOH. It all depends on the compound of course, and often knowledge is obtained by trial and error. It is advised to start with the least harsh conditions. When hydrolysis is complete, isolation of the final compound is done by evaporating the solvent (1,4-dioxane), acidify with HCl or an ion exchange resin, and filt

Column chromatography: collection of samples

Illustration of a small column (column chromatography) Two pictures are shown of column chromatography. The first one showing the column, using mobile phase dichloromethane. Below the collected samples. Samples were collected in penicillin flasks. Every 10 samples, thin layer-chromatography (TLC) was done to monitor the column, and see which samples contained to desired isolated compound. The chosen column was small, since the sample size was also relatively small.