Wikipedia:Reference desk/Archives/Science/2010 May 14

= May 14 =

Graupel... but not?
From what I've read here and on other sites, graupel is falling snow that has a nucleus of a snowflake but is otherwise an agglomerate of water condensation in the shape of a tiny ball. However, a lot of the examples seem to make graupel out to be heavy and pellet-like. What I'm wondering is if there is a word or descriptor for graupel-like snow that is as light as a feather... it simply won't land if there's enough of a breeze. I've been describing this snow as "styrofoam"-like to people I know, but no one has seemed to have seen it (rather, they just weren't paying attention). The coolest time I saw it was during a thunderstorm, there was thunder and the sky was full of floating super-light balls of rime (?) (near Denver, Colorado). They're super-light in mass. Graupel itself accumulates like ball bearings on the ground and you can roll the pieces around together until they melt (I was doing that just a couple days ago, in fact), but I'm really looking for a description on what the super-light stuff may be... or just confirmation that it's a type of graupel that hasn't been described on Wikipedia yet. –  Ker αun oςc op ia◁ galaxies  00:28, 14 May 2010 (UTC)
 * Actually, I think Graupel is what you are looking for. The heavier ice pellets are called sleet in the U.S.  Perhaps the two terms get confused.  -- Jayron  32  01:23, 14 May 2010 (UTC)


 * Hmm, okay. A case of "right under my nose", then! –  Ker αun oςc op ia◁ galaxies  02:01, 14 May 2010 (UTC)


 * Snow pellets? ~ A H  1 (TCU) 02:59, 15 May 2010 (UTC)

translate
whats going on in this vid   http://www.nothingtoxic.com/media/1273711451/Indian_Cop_Punches_The_Spit_Out_Of_Woman  —Preceding unsigned comment added by Tom12350 (talk • contribs) 02:20, 14 May 2010 (UTC)
 * I think you want the language desk but since you're on the science desk... I observed a caption to the video which stated: "She was there to report domestic violence, and he was just trying to make sure he understood exactly what had happened!"  Dismas |(talk) 04:10, 14 May 2010 (UTC)

geographic centers of population
Where can I find a map with the longitude and latitude of the center of population for the world and for each continent, political divisions, etc. 71.100.0.29 (talk) 06:58, 14 May 2010 (UTC)
 * Sounds like something that is (or at least based on information available from links at) the center of population article. DMacks (talk) 09:52, 14 May 2010 (UTC)


 * Bear in mind that continents are not precisely defined.--Shantavira|feed me 13:14, 14 May 2010 (UTC)

Fuel question
we know that the only fuel that work without oxgen is uranium,here is the question how is the hydrogen in the star burn with out oxgen in the space? ex:sun it contain about 74% of hydrogen and 0.77% of oxgen?

thanks for help. —Preceding unsigned comment added by Khaled khallaf (talk • contribs) 09:25, 14 May 2010 (UTC)
 * Uranium is not the only fuel that works without oxygen. Many things can burn (like a flame) without oxygen, just need something that is chemically like oxygen in the reaction. And nuclear reactions are a totally kind of reaction from chemical ones--the "burning" of hydrogen in a star is nothing like combustion. Both release heat and/or light, but the actual process (and therefore the requirements) are different. The Star section has some of the actual reactions that occur, and you can see exactly what elements are (and are not) required. DMacks (talk) 09:46, 14 May 2010 (UTC)
 * Uranium releases energy when its unstable heavy nuclei split apart. Hydrogen releases energy when its light nuclei combine. It also releases energy when it is oxidized (e.g. burned) by oxygen. Hydrocarbons are also oxidized by oxygen, as well as food in the human body. Generators release electrical energy when a magnet moves past wire coils. --Chemicalinterest (talk) 12:50, 14 May 2010 (UTC)


 * There are certainly many 'fuels' that work without oxygen. But you are talking about three very different ways of extracting energy from a 'fuel':


 * When you 'burn' things - they react chemically (typically with oxygen - but there are other possibilities) - releasing chemical bond energies between atoms as heat and light. When you burn hydrogen with oxygen, it forms water and releases some heat in the process.
 * When you use uranium in a nuclear power plant or a bomb, the energy is released from within the atoms themselves. These very large and unstable atoms simply fall apart, releasing energy in the process (that's why uranium is radioactive) - we do some devious trickery to encourage them to do that more quickly than they would naturally - and we get a LOT of energy out.  If you actually set light to some uranium - 'burning it' with oxygen in the conventional sense, then you'd get very little (if any) energy out of it. (Actually, I'm not sure - but you might even have to put some energy INTO it to make it react with oxygen...I'm not a chemist, so I don't know for sure).
 * Uranium, like most metals, will burn in the conventional sense. See Here.  But  it releases nowhere near as much energy as if you fission (is that a verb?) it. Buddy431 (talk) 15:37, 14 May 2010 (UTC)
 * The hydrogen in the sun produces energy in yet a third way - the enormous gravity of the sun crushes these very small hydrogen atoms together so tightly that they are forced to combine into heavier atoms (helium, in this case) - leaving some left-over bits of atom that are turned into energy. This produces even more energy than messing around with uranium or plutonium.  There is a lot of research into creating useful 'fusion energy' here on earth - but it's taking a long time to produce anything useful because it's really difficult to do if you aren't inside a star!


 * Those three methods of extracting energy are totally different. We really shouldn't talk about 'burning' uranium or hydrogen in those last two cases.  What happens with uranium and plutonium is a "fission reaction", what happens with hydrogen in the sun is a "fusion reaction".  Talking about the sun 'burning hydrogen' or a nuclear reactor 'burning uranium' is sloppy and confusing - what it's really doing is "fissioning uranium" and "fusing hydrogen into helium".  The sun also (albeit much less often) fuses helium into yet bigger atoms - and those into bigger still atoms...and that's how come there is a small amount of oxygen in the sun - it's actually being formed under crushing pressure and vast heat from the hydrogen and helium that makes up much of the sun. SteveBaker (talk) 23:18, 14 May 2010 (UTC)


 * Mmm. There's a problem of people thinking that they're more different than they really are. For example, a lot of people think that fission and fusion convert mass into energy and ordinary burning doesn't. Really, the idea in both cases is exactly the same: you break and/or form some bonds such that the total bond energy afterwards is less than the total bond energy before. It's just that in one case it's electromagnetic bonds, while in the other case it's nuclear-force bonds. You get more energy from the nuclear force because it's stronger, not because anything fundamentally different is happening. I like the term "nuclear burning" to describe what happens in fission reactors and in the Sun. -- BenRG (talk) 09:54, 15 May 2010 (UTC)
 * While you are certainly right - one has to tailor the level of explanation to the level of the audience. In this case, our OP is confused and wonders why the sun doesn't need oxygen to burn hydrogen.  The detail level of your explanation serves to muddy the waters and confuse still further - is there a difference between a chemical change and a fission or fusion reaction?  Hell yes!  Not: Well, not really.  My explanation answers the question - even if it leaves some small details unstated.  That is the art of answering Ref Desk questions.  Tell the person what they need to know - don't confuse them with unnecessary complications. SteveBaker (talk) 16:45, 15 May 2010 (UTC)

Spontaneous Generation
When I think about the obsolete theory of spontaneous generation, I have to wonder how any enlightened man at any point in history ever thought this theory to be true. Everyone could see that plants and animals came from other plants and animals (obviously only on the macroscopic level) and that living things NEVER have been observed coming from non-living things. What sort of rationale did people make up in their heads to justify this theory?--160.36.38.182 (talk) 12:48, 14 May 2010 (UTC)
 * When they saw meat just sitting out rotting with flies flying around it, then maggots "appeared" on it. Instead of studying how the maggots came, they assumed it came from rotten meat. --Chemicalinterest (talk) 12:51, 14 May 2010 (UTC)
 * Of course, "enlightened men" are spread precariously thin in history (and today). But indeed, before microscopy was invented, on could observe "life" spontaneously springing up from "dead" matter without any visible sign of where it came from. Keeping things sterile enough that no unexpected life crops up is hard enough today, when we understand the processes and necessary hygiene. As evidence, see the various food scandals that crop up over and over again. --Stephan Schulz (talk) 13:02, 14 May 2010 (UTC)


 * It takes pretty precise work to disprove the theory. You have to be extremely careful that insects do not contaminate your sample before you realize it, because you won't be able to detect their eggs with the naked eye in many cases. Fruit flies are a great example. Leave some fruit out (esp. bananas) for a few days too long. Suddenly you'll have a kitchen full of tiny gnats. Where'd they come from? Did one sneak in when you weren't looking? Or were the eggs there all along? Either way, in a somewhat magical way, you have a huge number of little creatures. When you say that it has "never been observed", that's just tautological — you're saying it hasn't been observed because you know it doesn't happen (and you know that the fruit flies or maggots got there elsewhere). The 18th century natural philosopher would say, "hey man—it's been observed, and it's easy to observe." --Mr.98 (talk) 13:09, 14 May 2010 (UTC)

I can see your point with flys and maggots. But why make up the such things like, for example, that turtles come from rocks when we can see them having sex and laying eggs and the baby turtles coming from those eggs?--160.36.38.182 (talk) 13:16, 14 May 2010 (UTC)
 * Until Pasteur's work with meat in narrow-necked flasks, the prevailing thought was that life often spontaneously arose, including field-mice from bundles of hay. You'd thought they'd seen other domesticated mammals giving birth and extended it to mice. We have a good article on Spontaneous generation which discusses the history of thought on this. wp:whaaoe CS Miller (talk) 13:35, 14 May 2010 (UTC)


 * The problem is that you and I are bombarded with TV, Internet, books and journals in huge abundance - and even the least educated person from all but the worst 3rd world countries has been taught at a level far above what someone from the 17th century would have known. For all but the very rich, books were a rare and costly luxury - education was brief and strongly driven by the church - and communications were all-but non-existant.  We have microscopes that can see all the way down to individual atoms - they didn't have anything more powerful than a 3x magnifying hand-lens.


 * You say that we can see turtles having sex and laying eggs - but have you ever seen that in person? I certainly haven't.  I've seen it on TV - and I've read about it in books - and was probably taught about it in school...but no, I have never seen any of those things.  It's possible that someone who HAS seen it might have told me about it - but that depends on a mobile population and good communications - which certainly didn't exist back then.  When most people never strayed more than a day's walk from their place of birth - and only a few percent of people were literate - even true ideas spread very slowly.


 * The idea of "The Scientific Method" also was only just beginning to come together back then. They had not yet had the idea that you can't just guess that because turtles have hard shells, they must have come from rocks - but instead you have to do some careful experiments before you say that.  The whole idea that correlation does not imply causation is actually relatively recent - and it's an idea that the majority of people that I meet still don't understand.  If you see a hoard of fruit flies every time you see rotting fruit, it's easy to guess that the fruit somehow caused the flies to come into existence.


 * You might have seen one of your farm animals or a family member give birth - you'll have seen chickens hatching from eggs - but without the knowledge that all living things are evolved from the same source, how do you know that this also applies to turtles? They certainly look more closely related to rocks than to chickens.  Zoo's full of exotic animals belonged only to the very rich - mostly only to royalty.  In the 1600's, hardly anyone did long sea voyages - and those that did mostly came back with stories about mermaids and other such stuff.


 * I think you underestimate the power of information, communication, education and the scientific method. Without those tools, even the smartest people can't reason sensibly about the world they live in.


 * SteveBaker (talk) 13:48, 14 May 2010 (UTC)


 * Not to mention that if someone was educated, they look this information up in authoritative works by Aristotle and subsequent great thinkers throughout history. It's hard to argue with that sort of authority.  APL (talk) 14:10, 14 May 2010 (UTC)
 * And the somewhat less enlightened/educated would observe that the bible says that things that lay eggs are birds (I actually have no idea whether it says that...but it wouldn't surprise me - it says that bats are birds) - and arguing against THAT kind of authority could get you burned at the stake. SteveBaker (talk) 14:38, 14 May 2010 (UTC)

I actually have seen turtles having sex, have killed turtles with eggs in them, and have dug up turtle eggs. I have never seen turtles hatching, however. But, believe me, I get your point about the availability of knowledge today compared to then. —Preceding unsigned comment added by 160.36.38.182 (talk) 13:53, 14 May 2010 (UTC)
 * Sure, YOU may have done - but in a world without the Internet, you couldn't have told me that. If (in 17th century England) I had said that turtles come from rocks - then people may well have believed me because YOU can't tell either me or them that it's nonsense.  In reality, you would not even know that I'm telling people that - until some book that I'd maybe written on the subject happened to pop up in a rich man's library someplace where you had the rare privilage to study.  Now you could maybe write a book saying that what I said was wrong because you'd seen turtles laying eggs and more turtles hatching from those eggs - and 20 years later, that book might show up in some library that I have access too - but since there are also books there saying that people have seen mermaids and sea monsters big enough to swallow entire ships...why would I believe you?   More to the point - why would people that I've convinced even read your book or hear your point of view unless someone tells them about it?   If they do hear about it - will they believe your preposterous claim that turtles are really birds because they lay eggs and have flippers like penguins?  I don't think so! SteveBaker (talk) 14:36, 14 May 2010 (UTC)
 * Another point is the level of transport, tourism, leasure time and other things means far more people are likely to have seen in person turtles laying eggs then previously. I don't know where the OP saw turtles (the IP looks up to the US) but there's a very good chance they wouldn't have had the opportunity to watch turtles laying eggs if they were living in the 17th century Nil Einne (talk) 16:39, 14 May 2010 (UTC)

Today we are faced with the opposite problem Count Iblis (talk) 14:03, 14 May 2010 (UTC)


 * To reiterate Steve's essential point, it's not so much that we have more knowledge today than they had then (we do, but that's beside the point), it's that generally speaking, we're more inclined to take the careful time and effort it takes to validate said knowledge (and have the means to do it). Most writers on what was called "natural history" were compilers of information, not researchers. They would write lots of letters and read lots of books. They would weigh what was said with what made sense to them. Rarely did they have the resources or will to actually do anything like experiments. If someone reliable told them something, they might consider it reliable. If lots of people said the same thing, they thought that was a good indication of its truthfulness. This isn't necessarily a bad approach—Darwin's works are filled with this approach, though he is fairly critical and did indeed like to do his own experiments when he could—but in some cases it definitely led to the case of an elaborate game of "telephone." Add to it that the natural world is strange—would you believe a Platypus existed?—and is full of crazy wonders, and you have what the philosophers would call a very problematic epistemic situation. It's not until the number of people working on these problems in a systematic way grows considerably and communications improve considerably that a lot of the nonsense gets weeded out. (Read: 19th century, when science professionalizes and stops being something that a handful of rich guys do in their spare time.) --Mr.98 (talk) 14:08, 14 May 2010 (UTC)


 * Certainly if you visit places like the Natural History Museum in London (which has been around for a very long time and has collections dating back to the 1600's) - when you get away from the fancier, modern parts of the museum, you can see that the "scientists" from a couple of hundred years ago were more like stamp collectors than modern scientists. They collected every kind of animal and plant they could - preserved them in jars of formaldehyde or kept the skeletons or used taxidermy to preserve their outer appearances - and they'd make beautiful drawings of their anatomy.  But that's about where it stopped.  At the natural history museum - you can see cases and cases of butterflies and beautifully posed stuffed birds and such like - but almost nobody from that time was doing any reasoning about what they'd collected.  They categorized and preserved - but it was quite literally just like stamp collecting.  SteveBaker (talk) 14:25, 14 May 2010 (UTC)

The OP has no grounds for their bewonderment. Large numbers of people today think that a spontaneous generation of living things occurred either in an Abiogenesis event or literally as related in a creation story, and they are almost all regarded as enlightened by their friends. Cuddlyable3 (talk) 14:21, 14 May 2010 (UTC)

If, to all appearances, organisms seem to 'generate spontaneously', well why not just go with that until proved differently? There's no use fretting over these things when there simply isn't any evidence to the contrary. Vranak (talk) 14:39, 14 May 2010 (UTC)
 * Enlightened persons of the 18th and 19th century had seen weevils appear in a sealed container of flour, or other tiny living things appear in materials which had apparently not been accessible to small living creatures. (I have found this to happen, even when the plastic container of flour has been sealed with an apparently airtight lid for months. I "know better", just as I "know" that my senses deceive me when it appears that a magician can make things appear and disappear). Scientists even of the mid 19th century tried boiling sealed flasks with hay infusion, and found that some microscopic life grew in it and it became cloudy and smelled bad. It turned out that it is hard to sterilize hay infusion, compared to broth, and that "boiled" is not necessarily "sterilized." What microscopic fraction of the adults of 1830 had ever seen some of the phenomena we think are "everyday knowledge" from watching nature programs on TV, which distill thousands of hours of observation and filming into a few seconds of "common knowledge" of  how little animals reproduce? In the 20th century when I was about 5 someone told me that a horse hair placed in water would become a little "hair snake" and I immediately tried the experiment, with negative results. Not everyone has the inclination, time or resources to try and replicate experiments or observations that are "common knowledge." Edison (talk) 15:14, 14 May 2010 (UTC)

new elements
Is there any possibility of discovering one or more new elements that are stable (at least with a half life measured in years rather then ms)? Googlemeister (talk) 14:26, 14 May 2010 (UTC)


 * Yes! Very much so.  See Island of stability - very recently, a synthetic element was made that is fairly stable compared to other massive elements.  However, what doesn't seem likely is that any such elements will be found in nature...if they were there, I'm pretty sure we'd know it - unless maybe they only exist in 'exotic' places like the hearts of stars or something. SteveBaker (talk) 14:42, 14 May 2010 (UTC)


 * Or in the detritus left over after supernovae. --Mr.98 (talk) 15:41, 14 May 2010 (UTC)
 * Everything past iron only exists in the detritus of a supernovae. Of course, these elements may have half-lives short enough that there's none left by the time it forms into part of a planet. — DanielLC 01:18, 15 May 2010 (UTC)
 * Not quite. Heavier elements can be formed in stars via the S-process; approximately half of the heavier-than-iron matter in the universe is believed to be formed this way.  And heavier elements can leave a star by means other than supernovae: novas and the rarer luminous red novas.--Atemperman (talk) 05:11, 17 May 2010 (UTC)


 * No! The Island of stability indicates only the stability against beta decay and alpha decay, spontaneous fission is not plotted in that chart. There might be elements out there with a half life of hours for beta decay and alpha decay, but they will undergo spontaneous fission in miliseconds. If the theories about the atomic nucleus are right it is very unlikely to find any elements with a significant half life.--Stone (talk) 17:34, 14 May 2010 (UTC)
 * Our article does claims some people suggest millions of years is a possibility sourced to Nil Einne (talk) 00:39, 17 May 2010 (UTC)

ant
When a queen ant lays her first egg, it's tiny. How does it grow bigger and into a cocoon and then an ant without any feeding? Because the queen ant lives alone in her newly dug nest and doesn't eat or drink for months until the baby ants hatch and bring her food. —Preceding unsigned comment added by KELITORPO (talk • contribs) 15:09, 14 May 2010 (UTC)
 * Individual ants store food in their crops and pass it to larvae via Trophallaxis. This is explained at Ant. Zain Ebrahim (talk) 15:40, 14 May 2010 (UTC)


 * The queen initially feeds the first ants using food manufactured from her own fat stores and the metabolism of her wing muscles (she no longer needs them). The first batch of baby ants are exceptionally weak and feeble, just enough to start things up. (I don't think this takes months.) Check out E.O. Wilson's engaging (fictionalized) account of this ("Trailhead") from a recent New Yorker. --Mr.98 (talk) 15:46, 14 May 2010 (UTC)

re:donkeys
I know that a male donkey is a jack, and a female is a jenny, or jennet... What do you call a gelded donkey. A gelded horse is a gelding, for example. Thanks Gqe9670 (talk) 17:50, 14 May 2010 (UTC)
 * Our article Gelding says that it can be used to apply to donkeys as well. Vimescarrot (talk) 18:21, 14 May 2010 (UTC)

Medical Breakthroughs
Have their been any diseases cured or medical breakthroughs in the past ten years? Why haven't we cured aids or malaria yet? Where are the results of stem cells and gene threapy that have a few years away for over a decade?! TheFutureAwaits (talk) 22:47, 14 May 2010 (UTC)


 * Malaria actually is curable, it's just that the majority of those who have it can't afford the treatment. AIDS will probably never be cured, it will require social changes to stop its spread. Gene therapy is still being worked on, it has had some successes, but is also dangerous which slowed research. Stem cell treatment was never just a few years away, it has just been massively politicized. People who support abortion did not want any restrictions that might lead to bans on abortion, so they made tons of pie in the sky promises about stem cell therapy to try to drum up support. And googling "medical breakthroughs" found tons of articles with a large variety of lists. Ariel. (talk) 23:48, 14 May 2010 (UTC)


 * We make medical breakthroughs all the time, new drugs with better efficacies and fewer side effects. There are certain diseases which continue to elude us, the big one being HIV/AIDS. We haven't found a way to cure it yet because it happens to destroy the one thing our body needs to get rid of it. The only currently percievable way to get rid of HIV is to prevent all infected partners from having sexual intercourse with anyone who isn't infected--a task inconceivable beyond imagination. Our only hope is that some day researchers will find a revolutionary breakthrough in the way our immune systems works, or with a drug which can target the virus and kill it and prevent it replicating inside our own cells. Regards, --— Cyclonenim | Chat 00:01, 15 May 2010 (UTC)


 * I will note that HIV infection is in many cases treatable, though not generally considered curable. Where HAART is available, the average expected time to progression from HIV infection to full-blown AIDS is now more than thirty years(!)  There are tantalizing hints of future curative therapies, however.  CCR5 is a receptor protein expressed on the surface of immune system T cells.  It's been known for a while that a small fraction of the human population is innately immune to HIV infection, because those people carry a mutation in the CCR5 protein; this mutation – CCR5-Δ32 – prevents entry of the virus into T cells.  A number of companies now have drugs in the pipeline which are designed to bind to CCR5 and thereby prevent cell-to-cell transmission of HIV, ultimately curing the disease.  Last year a clinical gene therapy trial began, in which the CCR5 gene was to be knocked out in HIV-positive patients.  Finally, in 2008, a German HIV-positive leukemia patient (which would normally sound like a cruel medical joke) was cured of both conditions by bone marrow transplant from a donor who carried the mutant CCR5.  (The risks of bone marrow transplantation are rather high, and the donor pool is limited, so this particular therapeutic approach is unlikely to be adapted for individuals who aren't receiving such a transplant for other reasons.)  I'll let the OP decide which, if any, of those approaches might constitute a 'breakthrough'.  TenOfAllTrades(talk) 02:17, 15 May 2010 (UTC)


 * See SuperAIDS. There have been many advancements in treating cancer, for example DCA and Madagascar periwinkle but no complete cures or breakthroughs. ~ A H  1 (TCU) 02:54, 15 May 2010 (UTC)
 * Whee, statistical and disease-progression projections! "Where HAART is available, the average expected time to progression from HIV infection to full-blown AIDS is now more than thirty years(!)" AIDS wasn't even known 30 years ago, HIV as the infective agent wasn't discovered until a few years later, and the first retroviral wasn't approved for HIV/AIDS until several years after that. Average 30-year expectation for something that's only been around 24 years? DMacks (talk) 16:37, 15 May 2010 (UTC)
 * The figure is actually closer to twenty years. Regards, --— Cyclonenim | Chat  01:39, 16 May 2010 (UTC)

acetic acid
which is stronger 5% acetic acid or 10% sulfuric acid —Preceding unsigned comment added by Tom12350 (talk • contribs) 22:52, 14 May 2010 (UTC)
 * 10% sulfuric acid; it's a strong acid. 5% acetic acid is what household vinegar typically is. -- Flyguy649 talk 23:22, 14 May 2010 (UTC)

yes but white vinegar is pretty strong and 10% sulfuric acid  is a very dilute solution  —Preceding unsigned comment added by Tom12350 (talk • contribs) 23:32, 14 May 2010 (UTC)


 * No. Vinegar is 5% acetic acid. (Acetic acid is a weak acid). A 5% sulfuric acid solution (~1M) has a pH of 0.3 while a 5% acetic acid (i.e. household vinegar) has a pH of ~2.4. There are loads of google refs for these figures. -- Flyguy649 talk 23:34, 14 May 2010 (UTC)


 * You need to explain what you mean by "pretty strong" here. "Strong acid" has a specific meaning (see the link Flyguy provided). However if you're simply looking at dilution (which makes no sense when talking about acid "strength") a 10% solution of something is self-evidently twice as "strong" as a 5% solution of something, so what are you asking? Please clarify your question. Tonywalton Talk 23:40, 14 May 2010 (UTC)

The Vinegar smells stronger than the sulfuric acid though. Graeme Bartlett (talk) 23:51, 14 May 2010 (UTC)


 * I don't know about that. At sufficient concentrations, sulfuric acid fumes, and its quite acrid smelling.  But a 5% acetic acid solution will only have a pH of 4 or 5 or so (pH = -log (SQRT (Ka * molar concentration)) for anyone that wants to calculate).  As a strong acid, a 10% sulfuric acid solution will have a pH probably much closer to 1 or 0.  -- Jayron  32  00:12, 15 May 2010 (UTC)


 * Carboxylic acids tend to have strong odors. Did you ever smell butyric acid? --Chemicalinterest (talk) 00:21, 15 May 2010 (UTC)

when i wash a surface with vinegar unless i rinse it well it still smells like vinegar and has a acidic feeling to it when it dries. so it leaves a residue when it dries. does 10% sulfuric acid also leave a residue when it dries? —Preceding unsigned comment added by Tom12350 (talk • contribs) 01:46, 15 May 2010 (UTC)
 * The sulfuric acid will get more and more concentrated, and then absorb water. Eventually it should all evaporate over time. Graeme Bartlett (talk) 12:39, 15 May 2010 (UTC)
 * 10% sulfuric acid probably wouldn't evaporate very quickly, since sulfuric acid has a strong attraction for water. Acetic acid probably precipitates out of the solution when a surface with it on it is dried. BTW, you can wash it with sodium bicarbonate solution to remove odors of any acid, or even the odor of ammonia. --Chemicalinterest (talk) 14:24, 15 May 2010 (UTC)