hermanntrude

i was thinking of the common ion and uncommon ion effects

i'm not sure if auric acid exists. [ce]HAuCl4[/ce] is hydrochloroauric acid, so i guess the bromo one is hydrobromoauric acid

If you need to check the rules, check them. they're on the forum for your convenience.

hmm... well it's written in the textbook i teach from (which was written by a self-important ignorant prick), that when light goes from a less dense to a more dense medium it is refracted away from the normal, because the speed of the light is lowered by different amounts, and vice versa. I'd like to get to the bottom of this, since I have known this textbook to be wrong before, and I need to know where the wrong parts are

I'm aware that it's more complicated than that, and unfortunately I have to teach my students annually about refractive indexes without going into any of the interesting details. Anyway Ijust thought that the density might give us a first approximation well i guess we wont know until someone does the remake. Certainly it seems we have a good case for reducing the quantity of the test material to a minimum to reduce any changes in the speed of the waves to another minimum

moved to inorganic. I havent a clue how you'd make this stuff to be honest

water is unique and everywhere you look on earth. the supply will never run out, although the supply of clean, safe, drinkable water for human consumption might, in some places. That'd be our problem, rather than the earth's

The speed of light is related somehow (not sure exactly how) to the density of the medium. The speed of light in water is about 2.2 (i think?) x 10^8 m/s, and since chocolate has a density much closer to that of water than that of air or vaccuum, we might expect the value to be in the mid to low 2's rather than 3, although there is further complication in that the wave probably doesn't travel entirely through chocolate that sounds interesting. However, your predictions defy my limited knowledge of wave mechanics. If you are right, hopefully the albumin adaptation will help to prove it.

mooeypoo your statement that you got a 6% error is based on the assumption that the speed of ligth should be that of the speed of light in a vaccuum, which is not necessarily true in the case of a bar of chocolate. the use of a thin layer of egg white is probably going to remove that uncertainty at the least

YT is your figure for pure water or for sea water, which contains other salts?

there is also mass/volume %, which is commonly used in pharmaceuticals whichever you require, the calculation is easy. For instance, if you wanted mass percent, calculate the masses of both the bromine and the water separately, then divide the mass of bromine by the mass of water, then multiply by one hundred. if you wanted volume percent, just do the same with volumes instead of masses

this depends on the purity and temperature of the water and also to some extent the availabilityof crystallization nuclei

egg is a good idea i think

there certainly is an element of uncertainty in the measurement of the distance between nodes when using chocolate. Mostly because as soon as the chocolate melts it flows, and also because it doesn't ONLY melt at the nodes, which makes the melted area larger than desired. These are the reasons I suggested using a gel in which the first boiling, rather than the first melting can be observed, AND because the gel will crack, the positing of the first few bubbles will be recorded for later observation. Your comment about using a metric ruler is totally nonsensical and I can't really say anything more about it.

I wondered to myself last night about this experiment and how it could be improved. I was thinking that since the chocolate bar is liquidified it spreads, and since it is opaque, one cannot see the exact point of meltage (neologism, I know). Perhaps the experiment could be improved by the use of a transparent substance, perhaps a gel? so when it starts to boil the cracks in the gel stay where they are and can be seen from outside

fair enough, I quit. it's all a moot point anyway since we're the only ones left even posting in this thread, and no-one really cared in the first place.

neither pole, nope. Actually at a lower latitude than you approximately 49°40'N 55°15'W

nevertheless, it's not always obvious that what you're buying is NaOH, since on the fron tin giant letters it says "mr Muscle" or "wonderclean supreme winter-fresh" or something equally dumb, and then on the back in tiny letters because the law requires that they do so, it says that it contains NaOH, which some people read and some do not. Again i'd like to point out that we're only debating the validity of a "very", not anything particularly important

arizona? nope. No lizards here

some (or none) of you may have been wondering where i've been well here's some photos

it'd be in any decent chemistry textbook... i just can't remember it offhand

thread moved to homework help where it should have been in the first place. Also please note that even when it's NOT in the right place, a thread asking for help with a project or homework or anything similar should NOT be answered immediately with specific detailed answers Give some clues, perhaps refer the asker to a useful website or a textbook chapter, for instance, use some keywords.

YOU know that oven cleaner is NaOH, he might not. My point is that it's a strong base. The "very" might or might not have been superfluous. Don't be such a pendant.

to understand the sizes of ions and atoms, you must consider the numbers of electrons, the numbers of protons and also the number of electrons which shield any given electron from the positively charged nucleus. I don't remember the exact details but some electrons are better at shielding than others

bear in mind that any sizes given to atoms or molecules are somewhat arbitrary, since the positions of the electrons can only be determined probabilistically, meaning that atoms and molecules could be considered to have infinite size, but just massively higher electron density at the centres.