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63

It does. You would find the average percentage of the atmosphere that is argon is very slightly higher at the floor of valleys. However, bear in mind first of all it wouldn't be anywhere near a complete stratification -- a layer of pure argon, then another of pure N2, and so on. A mixture of nearly ideal gases doesn't do that, at least at equilibrium, ...

12

As far as I can tell there are two material types used for this - pure ceramics or ceramic mixtures that are designed to break and be replaced, and composite metal + ceramic materials that are designed to be able to handle a couple of rounds without losing too much effectiveness. There are also techniques involving purely metal layers in overlapping ...

12

Here are factors that would speed up rusting: Presence of water: make sure that the iron is wet. Presence of oxygen: make sure the iron have access to air (the dissolved oxygen in water also works). Presence of metal below iron in the metal reactivity series (see the picture below): usually copper is used. Tie copper to iron. Make sure that they are in ...

12

It seems like an idea of using magnesium anthracene systems for the $\ce{MgH2}$ production persisted since 1980s [1] till late 2000s, when new more efficient method with better scalability for industrial use was established. One of the recent reviews in hydrogen-storage applications [2, p. 220] compares the older two-step process of $\ce{MgH2}$ synthesis: ...

10

Yes, selenium sulfide is well known and it is used in anti-dandruff shampoo but other sulfur-containing selenium compounds are not really well known. Selenium sulfate, properly selenium(II) sulfate, $\ce{SeSO4}$ is unknown to the best of my knowledge. The analogous tellurium compound has been synthesized recently, but still it is not a proper sulfate ...

9

You could proceed from either end member of the olivine solid series and yield $\ce{SiO2}$ as you suggest. However, I'd consider mechanisms that have been researched in the course of studying so-called mineral sequestration in addition to what you've written, especially considering the energy requirements you propose: the mineral sequestration reactions are ...

7

In my estimation, this is basically marketing nonsense. If you examine the list of ingredients, the primary active agent is invariably some aluminum or aluminum-zirconium salt, which act as anti-perspirants primarily by the mechanical actions of shrinking pores (due to their astringency) and clogging ducts in the apocrine glands. Listed among the inactive ...

7

Perfluorocarbons would be a possibility, $\ce{(-CF2-)_{n}}$, they contain only carbon and fluorine and are relatively low cost and widely available in large quantities. They are inert (e.g. non-reactive) and depending upon chain length and structure, you could pick one that can be warmed up nicely to a bath temperature. They are also used industrially in ...

7

The sodium–sulfur battery is already in use for power leveling and other stationary applications, such as a 1.2 MWh installation in WV, USA. The Ford Ecostar did use a Na-S battery, but it did not have sufficient energy for distant travel (and some of the experimental batteries caught fire, but so do Li-ion cells on occasion. Oops!). Sodium-ion batteries ...

7

Ullmann’s Encyclopedia of Industrial Chemistry lists numerous components of commercial paints: dyes, pigments, extenders organic solvents, water, coalescing agents binders plasticizers paint additives (levelling agents, film-formation promoters, wetting agents, dispersants, antisettling agents, antifoaming agents, catalysts, antifloating and antiflooding ...

7

Here's a less-known effect: Iron or steel exposed to iodine vapors will rust within hours. Also, in a draft-free room, iodine crystals placed well above an iron object will evaporate, creating a descending vapor-plume which rusts everything directly below. Or just use overkill: affix a sack of black iodine powder over the steel to be rusted. (Also, ...

6

In the lead battery it is very important that the electrodes transform into insoluble lead sulfate when discharged, especially at the cathode where lead(IV) oxide is turning into lead(II) sulfate. Consider the two half reactions of the lead-acid battery: $$\ce{Pb(s) + HSO4−(aq) → \color{red}{PbSO4(s)} + H+ (aq) + 2e−}$$ \ce{\color{red}{PbO2(s)} + HSO4−(aq)...

5

There is relatively little research in sodium ion batteries, and as a result, breakthroughs in sodium battery technology are lacking. Recently, that has changed, and more scientists are looking into the potential of sodium ion batteries. However, the Na-ion battery's biggest drawback is its slow charge and discharge rates. This makes them impractical for ...

5

There are thermochromic materials that change color in response to heat photochromic materials that change color in response to light and electrochromic materials than change color in response to an applied electric field. All of these materials are sub-categories of Smart Glass. I suspect that electric field sensitive Smart Glass materials are what you ...

5

The previous answer is not really helpful because you would need huge amounts of CO2 which are not available on the moon. You need 2 moles of CO2 to generate 1 moles of SiO2. You simply do not have that amounts of CO2. Furthermore, assuming you do someone get that CO2, you need to physically separate the Mg and Fe carbonates from the silica. One way would ...

4

Sounds like you're referring to plasma waste conversion. If you heat matter to 4-figure temperatures all molecular bonds are broken and you have a gaseous mass of dissociated atoms. It is theoretically possible to extract the constituent elements from the plasma. If you want to preserve a particular element then the cooling of the plasma has to be ...

4

One approach would be to use various solvents. You would require solvents in which your various stains were soluble in. Alcohols / water would be suitable to dissolve the soda. Whereas an organic solvent would be suitable for washing away the gasoline. Though gasoline is typically colourless. Another approach would be to expose the paper to copious UV ...

4

The only volume that is important in the denominator of your equation is the total volume of solution; neither the volume of solute or solvent are explicitly relevant. Pragmatically, there is not likely to be much of a volume change when taking a concentrated solution and diluting it. So with reference to your question, you should add enough solvent to get ...

4

Burning or Incineration of Plastic cause carcinogenic chemical products if without suitable catalysts... To pyrolyze plastics such as polyethylene(PE) and polypropylene(PP) of olefin series, the catalysts with high cracking property are needed. Dioxin- carcinogenic and antibiotic effect to the environment. Flyash- may produce respiratory illnesses. Sulfur ...

4

Good quality quartz crystals for use in resonators can be found in nature, such as in Minas Gerais, Brazil. They can also be produced by crystallization in a hydrothermal process, simulating in the autoclave the same process that occurred over geologic epochs. You can easily grow your own Rochelle salt (potassium sodium tartrate, $\ce{KNaC4H4O6·4H2O}$) ...

4

In short-no your technique will not work. Reacting limestone with acid does not release enough energy to reach an appropriate temperature to ignite gunpowder and the acid would hinder combustion. Fear not though, spontaneous ignition may be achieved by mixing glycerol and potassium permanganate which works well and is a classic example. If you would like ...

4

In theory, yes it is possible. In practice, not really. First of all, the anorthite on the moon is never pure anorthite ($\ce{CaAl2Si2O8}$) but rather an anorthite-albite ($\ce{NaAlSi3O8}$) solid solution. That is, the single crystal contains both components. The diagram you added there, where it says "mole %"? The other stuff is albite. Now, back to glass ...

4

Andselisk's recommendations are great, but you'll save yourself a lot of trouble if you just throw all the erasers out. They get crud on them quickly and after a while, they put more back on the board than they wipe off. A microfiber cloth is much more effective, and works for a shockingly long time. I would bet on a filthy cloth over a brand new eraser, ...

4

Scrubbing the surface with an abrasive (powder) only makes it worse -- micro-scratches will accumulate pigments and dirt and overall promote further surface degradation. I would try the solvents (test on a small area first) in the following order: isopropanol, ethanol, acetone. Usually even cleaning wipes for glasses or computer screens do just fine. I also ...

3

Fine hexagonal boron nitride powder is hygroscopic, so this implies there might be some water in your system. According to Reaction of Hexagonal Boron Nitride Nano-crystals under Mild Hydrothermal Conditions "The reaction between water and hBN nano-crystals starts at very low pressure and temperature, i.e. 220 C and 1.0 MPa [~10 atmospheres]." Those ...

3

Probably not easily, especially if the concentrations are really low. Luminol + $\ce{H2O2}$ only works with blood because it's a catalytic reaction, i.e. it doesn't take much iron to create a lot of chemiluminescence. I'm not an organic chemist, but I'm not aware of any sort of similar reaction specific for this class of compounds. I did see this reaction: ...

3

Simple UV spectroscopy is not an option. You won't find anything at all above 254 nm - probably just a a weak band in the 220 nm range. Indolizidines are pretty dead in UV. Derivatisation towards a fluorescent compound would require clevage of a $\ce{C-N}$ bond, formally a dealkylation of the tertiary bridgehead amine. I have no idea if a reagent like 2-...

3

A radical, according to the IUPAC, has an unpaired electron. Radicals may or may not be ions. A molecular entity such as $\ce{.CH3}$, $\ce{.SnH3}$, $\ce{Cl.}$ possessing an unpaired electron. http://goldbook.iupac.org/R05066.html Contrary to your book's claim, the sodium ion is not considered a radical. It actually has all its electrons paired. It is ...

3

A mordant is a substance used to set dyes on fabrics or tissue sections by forming a coordination complex with the dye which then attaches to the fabric or tissue (source). Tannin is a biomolecule consisting of many carbohydrate and polyphenol residues with plenty of hydroxyl and carboxyl groups. Tannic acid is a common type of tannin: $\ce{Fe^{2+}}$ ...

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