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61

There are different angles this question can be answered: Chemical point of view: A full analysis of a totally unknown mixture is painful and extremely costly. It is always helpful to know how many components you are looking for; what types etc. In this case, it is not enough to analyse the elemental composition or some pure elements, but Coke contains a lot ...

56

As Nilay Ghosh said, nitrogen is cheap. Very cheap. Neon is expensive. Argon is cheaper than neon, but considerably more expensive than nitrogen. Helium is also expensive and needs to be used wisely, for important things, e.g., cryogenics. And hydrogen! I can just see the ads: “Buy our chips: they are lighter than air! But avoid open flames and sparks unless ...

52

The starch forms a loosely bonded network that traps water vapor and air into a foamy mass, which expands rapidly as it heats up. Starch is made of glucose polymers (amylopectin is one of them, shown here): Some of the chains are branched, some are linear, but they all have $\ce{-OH}$ groups which can form hydrogen bonds with each other. Let's follow some ...

50

The "fishy" odor that you're familiar with is brought about by a whole bunch of compounds, and not any single one. Then again, if we were to narrow this down a bit, we could say that simple nitrogen compounds are the main culprits. But suppose we want to blame only a single compound for the delightfully pungent odor of rotting fish, and we couldn't be ...

46

Not mentioned yet: nitrogen is entirely non-toxic, environmentally friendly, does not contribute to global warming or ozone depletion. In very good approximation, nitrogen is just air with the oxygen removed that would oxidize the contents. The usual production process consists of liquefying air, distilling it, and then selling the gases separately. This ...

42

There are 2 cases, both related to the acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice. Fish, especially sea fish, naturally contain trimethylamine-N-oxide $\ce{(CH3)3N-O}$ that, after death, gets enzymatically reduced to trimethylamine $\ce{(CH3)3N}$, the source of ammonia-like fish odour. Trimethylamine N-oxide ...

41

There are two ways to efficiently make an aerosol product: Use a gas that liquifies under the pressure inside the can. For example, butane lighters. Nitrogen is one of the "fixed gases", meaning it's a gas under most conditions (but take a look at the temperatures and pressures needed for liquid nitrogen—it's not going to ever be found in consumer products)....

33

It is not proven that "sugar makes your body acidic"! Your body's pH is very tightly regulated by the body's internal systems; it is also different in different parts of the body - the stomach is acidic (1.0-2.5), the intestine are mildly basic (jejunem 7-9) terminal ileum 7.5 reference here. Blood pH is 7.35, and any deviation from this is indicative of ...

30

If you go to https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:01990L0496-20081211&qid=1580028914722&from=EN you will see a fairly extensive list of caloric compounds (screenshot pasted below). This list is probably not comprehensive -- likely there are many compounds we (which includes our gut bacteria) can metabolize for calories. ...

29

Sugar is made by repeatedly boiling and cooling cane syrup (or sugar beet syrup). After each cooling, the solution becomes supersaturated with respect to sucrose, causing sucrose to crystallize out of the "mother liquor" (the industrial term for the liquid solution from which crystals form). These crystals of "raw" sugar are heavily processed (washed in ...

27

According to Nitrous oxide, carbon dioxide, and their mixtures as propellants, Proc. Chem. Specialties Mtrs. Assoc., June 1950, page 45, William Strobach, $\ce{CO2}$ and $\ce{N2O}$ are both suitable because they each have some solubility in both the aqueous and oil phase of the cream emulsion. $85\%~\ce{N2O}/15\%~\ce{CO2}$ has the most preferable taste, ...

27

Substances that are gaseous down to, say, -10 are finite (and not very large) number. Of these, we want: Safe against ignition (so no hydrogen or gaseous hydrocarbons) Not poisonous (phosphine, arsine, carbon monoxide - out!) Not corrosive (chlorine, fluorine - sorry) Without unpleasant smell (hydrogen sulfide is no-go) Not related to processes of food ...

26

Technically, even simple water can cause rust, so nothing surprising here. However, spoilage of milk most probably produced a lot of organic acids (lactic acid and similar) which can speed up any corrosion process. Lactic fermentation is a natural fermentation process in milk, when bacteria start converting the sugar content of milk to lactic acid. It is not ...

26

The main substances that cause the yellowish color of the milk are carotenoids [1]. The main carotene involved is the beta-carotene coming from the feed that cows eat. Some studies have been carried on and it has been noticed that the milk with a more yellow tinge was collected during late spring and early summer when carotene levels are at a maximum [2] ...

26

Avoiding cooling again after keeping it ( for non critical products ) at room temperature is mainly to prevent forgetting it was not cold all the time and that it may not last as long as expected. Taking food from the fridge, you may not remember after a week or two that it was outside longer than it should have been. It can violate the safety by growth of ...

24

With modern technology it would be a relatively straightforward process to determine all of the ingredients in Coca Cola. It would require time and money, but very doable. My guess is that companies that compete with Coca Cola, like Pepsi, know exactly all of the ingredients in Coke. This is part of the process known as "reverse engineering" and is done ...

24

Coffee contains hundreds, if not thousands, of other compounds in addition to caffeine. Included among these other compounds are many acids. Many small, organic acids such as citric, malic, lactic, pyruvic and acetic acid are present, but both quinic acid and chlorogenic acid (and their derivatives) are usually present in even higher concentration. ...

24

No salt will be pure NaCl. Each will have some degree of other elements. The fact that the salt isn't white confirms there are other elements present. See Analysis of Gourmet Salts for the Presence of Heavy Metals which investigates 14 salts including two Himalayan salts. See especially "Table 3. Comparison of toxic elements in Table Salt". A "...

24

Measure the change in mass over time of the remaining liquid. Though some water will also evaporate, you can control for that by keeping the humidity near 100%. If you have to be precise, collect the outgassed $\ce{CO2}$ in a liquid-nitrogen cold trap. Check the mass of the condensate, which should equal that lost from the soda. Check purity, to be really ...

23

They're not exact numbers. These numbers aren't exact for three reasons: Each type of carb, protein, and fat has a different caloric value. These are overall averages for each class. Even if you were dealing with a single pure compound, the value couldn't be exact because there is individual variation in how much of that compound is metabolized based on ...

22

If you don't mind, I'll start with a more colloquial and hopfully not to lengthy explanation: Precious metals, such gold, do not corrode under "household conditions", others, such as iron or aluminium do. Rusting of iron is a typical example. Here, the corroded surface often is very porous and the corrosion carries on until the whole piece of metal is ...

22

The raisin has nucleation sites on it that allow bubbles of $\ce{CO2}$ to form. The raisin is light enough to be lifted by the bubbles as they push their way to the surface. As the bubbles are released into the atmosphere, the raisin once again sinks until more bubbles form on it. This will continue until the soda water has lost the majority of its dissolved ...

22

You got me curious, so I poked around a bit on this. First there is insoluble and then there is insoluble. The Wikipedia article on capsaicin lists its solubility as $\pu{0.0013 g}/\pu{100 mL}$ which is $13$ parts per million. So capsaicin is "relatively insoluble", but not wholly so. Second the Wikipedia article also points out that capsaicin itself is ...

21

Do not do it !! ( putting acidic, or rather any juice to copper bottles ) You are in danger of copper poisoning. Generally, by food processing laws, copper is not allowed to be in direct contact with food, as there is danger of copper contamination. Especially acidic liquids, like vinegar or citrus juices, directly slowly dissolve copper in presence of ...

21

Answer here from a quality manager in the pharmaceutical field in Europe. Pharmaceutical companies are obliged to perform stability tests for their products according to the relevant pharmaceutical (GMP) agency in your market (FDA/EMA/etc) and the international agreed guidelines like ICH Q1A-F and the WHO). These tests are carried out in stability chambers ...

21

Thousands of different chemicals, previously spatial separated, are mixed together after thermal death of cells, and kept at high temperature to react well. Final taste will depend on original system, but will develop by way unpredictable theoretically from basic principles. The answer for a particular biological source requires detailed knowledge about ...

20

This is a nice well-defined question, and luckily there is excellent data for which we can provide a quantitative answer. Richard Wolfenden's research group has sought for many years to characterize the spontaneous (i.e. not enzyme catalyzed) rate of many enzymatic reactions. In general this is so that the spontaneous rate can be compared to the enzyme-...

19

It doesn't make calcium carbonate rubbery, it removes the calcium carbonate. Egg shells are not purely calcium carbonate they are more like a composite with a continuous matrix of calcium carbonate and a smaller continuous matrix of protien. When you put the egg in vinegar, you etch away this calcium carbonate matrix leaving the formerly less noticeable ...

19

It is the temperature of the pan that matters not the flame The flame temperature is irrelevant if you are cooking in a vessel. the only temperature you need to worry about is the temperature of the surface of the pan (or–even more importantly–the temperature of the meat). The surface of the pan will rarely get above around 220 °C if you are monitoring it. ...

18

An eggshell is a complex structure. From Wikipedia: Boiling the egg removes the waxy cuticle from the outside of the egg, dissolves a small but not insignificant amount of calcium carbonate from the shell, damages the protein matrix that holds calcium carbonate crystals in place in the shell, and can disrupt or destroy the two shell membranes. All of ...

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