BenSon

yeah thats what the answer booklet said, and i can see the correct results for 2,3 and 4 carbons

 

but for carbon 1, shouldnt there be 4 bonds to it?

Yggdrasil is right, also if it was attached to another bond then none of those answers would be right because then carbon one would have a 0 charge and the only answer with 0 for the first carbon is answer (i) and that is clearly wrong.

~Scott

well i didn't see how this worked really, but anyways

This is how I think it works neutral water 10^-7 for H+ and OH-. The HCL is 10^-8, If you plug that value into the standard pH formula you get pH 8 wich isn't realy true because you've added acid to neutral water it should be slightly acidic. By adding the the two amounts of H+ ions together you get the true pH. As for why it is only for 5% rule, My guess is that if the acid is stronger and the H+ from the water is less then 5% then the difference is negligable so we don't calculate it.

Example:

Ph of 1x10^-4 M HCl"

We plug that into the normal formula

-log(1x10^-4)

=pH of 4

If we do it the same as the 5% rule we get

-log((1 x 10^-4)+(1x10^-7)

=pH of 3.999956

~Scott

Alrighty what do you need us for then ?

~Scott

for a pH value of 6.98 the concentartion of acid would have to be (1 x 10^-6.98 M), I think, does the answer have working out?

~Scott

-log (1x10^-8)

= pH of 8

~Scott

Do not let the speed of the reaction mislead you. Many metals, which react with acids, according to the electropositive series, do so very slowly. I have tried with iron, chromium, titanium, tin, etc. All react very slowly, even in 30% HCl or 30% H2SO4. Even zinc is not that fast. The only real fast one I found is magnesium and with some patience, aluminium also can be made to react fast in concentrated acids. Of course the alkali metals also are really fast.

I wan't realy surprised by the violence of the reaction more by how long it has been going for still moderately bubbling after 10 hours. But I am less surprised now that I found it to be 3.75mol/L

~Scott

Well I bit the bullet and titrated it with a syringe. The verdict is 3.75mol/L, thats sounds more like battery acid, then a wimpy 0.4

~Scott

Ok I got some car battery sulfuric a while ago and today I needed some hydrogen so I dumped a nail it 25ml. Well after I got the Hydrogen I needed I decided to leave the nail in there to see how much it would disolve. Here I am about 6 hours later and the nail is still moderately reacting. How concentrated do you think this acid is? The nail was not galvanised and it has been sitting at room temperture all day. I did some very rough calculations when I first got it and worked it to be about .4mol/L althought this calc was done rushidly and poorly. I can't be arsed titrating it so can anyone give me an idea on how conentrated you think it will be?

~Scott

The thing to take away from this thread is not the answer to the question, "Is string theory scientific?" The thing to take away from this thread is an awareness that the answer to that question depends crucially on one's own philosophy of science. I think that BenSon would agree to that much, too.

Too True

`Scott

Yeah you can mostly use the ionic charge and that will get you through alright. But there are exceptions such as superoxides, here is a quote from wiki these are the rules you should know when using oxidation numbers

There are a number of rules that can be used in determining the oxidation number of a molecule or ion:

The oxidation number of (neutral) atoms equal zero.

In neutral molecules, the sum of the oxidation numbers adds up to zero.

Fluorine always has a −1 oxidation number within compounds.

Oxygen has an oxidation number of −2 in compounds, except (i) in the presence of fluorine, in which fluorine's oxidation number takes precedence; (ii) in oxygen-oxygen bonds, where one oxygen must neutralize the other's charge; (iii) in peroxide compounds, in which it takes an oxidation number of −1; (iv) in superoxides, where oxygen has an oxidation number of −½.

Group I ions have an oxidation number equal to +1 within compounds.

Group II ions have an oxidation number of +2 within compounds.

Halogens, besides fluorine, generally have −1 oxidation numbers in compounds. This rule can be broken in the presence of oxygen or other halogens, where the oxidation numbers can be positive.

Hydrogen always has an oxidation number of +1 oxidation number in compounds, except in metal hydrides where instead it is −1.

Enjoy, I always foreget "Oxygen has an oxidation number of −2 in compounds, except (i) in the presence of fluorine, in which fluorine's oxidation number takes precedence;" that one

~Scott

The theory is purely mathematical, so if the theory could be shown to be mathematically inconsistent, it would be falsified, and therefore proven wrong.

To my knowledge string theory is mathematicly sound. That being said if the theory is not disproved mathematicly it should need to be tested in another way.

~Scott

Yeah thats right its just good to remeber some standard oxidation rules for common elements like oxygen and hydrogen, their oxidation numbers will change depending on what they have bonded to.

~Scott

I don't think it's true that there are no experiments that can test string theory. For one thing string theory predicts the spectrum of particles. If particles were found that do not conform to that prediction, that would be a clear case of falsification by experimentation.

Has anyone done this yet?

As for the predictions made by string theory that require higher energy machines than we currently have, that is a matter of engineering, not science. It does not imply that string theory is not testable in principle. I don't see the sense in classifying a theory as "scientific" or "unscientific" according to the state of the art of engineering. If we do that, then what is "unscientific" today will become "scientific" tomorrow, and this change takes place without any change in what string theorists actually do.

See where i've highlighted, to me this is not a problem, but for you it is. Ideas of what is scientific have been changing throughout history you have even used this as an example. Don't be so clamped done on your own definition or mine for that matter they will change with time.

Well I'm sorry you don't like it, but your personal opinion is in fact mistaken. There are a number of predictions of string theory that are testable in principle. Besides, I'm sure all the hard working scientists who do string theory wouldn't care too much for you contradicting their personal opinion that their life's work is scientific.

Well, here is yet another way in which we are different, I don't hold my personal opinion on topics which are unfalsifiable by definition above other peoples, arguing opinions on such topics is a futile exercise. I'm sorry if i've offended you i see your are a 'physics expert' is string theory your game? I'm sure that string theorists would disagree with me and thats their decision to make.

But I would agree that it must be possible to test the theory, at least in principle. I would not agree that the theory must be testable with current technology, as I explained in my last post.

I will say it again I disagree.

~Scott

No, you aren't getting it. In order for a theory to be considered scientific, it is not necessary that the predictions be "physically possible". Indeed, how do you even know what is "physically possible" apart from experimentation?

 

No, what is necessary is that the claims made by the theory be such that if the experiment goes against the prediction, then the theory is proven wrong.

 

More succinctly: In order for a theory to be considered scientific, it must make risky claims by which it can be proven wrong, if the theory is in fact wrong.

Look here is where our opinions differ, You say, "No, what is necessary is that the claims made by the theory be such that if the experiment goes against the prediction, then the theory is proven wrong." I say, there is no such experiment so the theory can't be proven wrong so by your definition it is not a theory.

Proving all of the claims wrong is not necessary. It is only necessary to prove one of the claims wrong. And as for "what experiment?", I don't know. It is not technologically feasible yet. But that has not one whit to do with whether the theory is scientific or not. A theory need not be true to be scientific. It only needs to make predictions that are experimentally contingent.

Where I highlighted is the difference between us, for me that is a prerequist.

As I said in my first post, a theory is considered "scientific" if it meets the condition of falsifiability

And as I've said i disagree with this.

And as for bracketing string theory with philosophy and religion, that is not right. Philosophy for the most part is conducted a priori, as opposed to science which is conudted a posteriori. And religion is unfalsifiable, even in principle.

That was a generalization in answer to a different question not adressed in this thread. The "bin" I put them in is based on my opinion of said theories religion ect. I dislike you saying my personal opinion is "not right" thats all I have to judge topics that have no evidence as you said are "unfalsifiable" this includes string theory (At least for the time being, as I've already said).

In order for this to make any sense at all, I suppose you would have to define what you mean by "philosophy" and '"theory". There are philosophical theories and there are scientific theories. The expression "for a philosophy to become theory" has no more meaning that the expression "for physics to become a theory".

Today 05:19 PM

I think it is apparent how I define philosophy and theory due to my previous comments you can work that one out for yourself.

~Scott

Originally posted by Tom Mattson, This is quite independent of whether or not it is technologically possible for the theory to be tested. It has to do with the logical structure of the theory itself.

 

Since string theory makes claims that are contingent on experimentation (whenever that experimental technology may become available), and by obtaining falsifying results the theory may in principle be proven wrong, I say that according to our best understanding of "what science is", yes, string theory is scientific.

While the predictions made by said theories may tie into the logical structure of that defintion of a theory. That is just the first step. The predictions made by a theory have not only to be theoreticaly possible to test but physically possible. Your saying that the claims made by string theory can be proven wrong by experimentation. I ask you, what experiment can prove wrong all the claims of string-theory? Once the "philosophy" can be tested (In real life) to be proved right or wrong whichever school of thought you choose, it becomes theory.

~Scott

Could any one tell me the process of experimentally increasing and deacreasing calcium concentration.

 

EDTA will be titrated with milk, water, and bodily fluid to find the Calcium concentration.

 

I need to alter the sample to either increase the concentration of calcium or decrease the concentraion and titrate the sample again with EDTA to find the new concentration of Calcium

EDTA will not only attach itself to Ca cations but also the Mg and Al ions as well. So if you are specificly looking for the concentration of calcium cations then you will need to use another indicator. But if you are looking for total water hardness then the EDTA will work fine. To dilute the samples just use a volumetric flask and pipettte, dilute with distilled water.

~Scott

just another note; perhaps it's me, but the only alcohols i have access to are (apparently) methyl, ethyl and isopropyl, and the only carboxylic acids i have access to are (apparently) ethanoic and 2-hydroxy-1,2,3-propanetricarboxylic acid (citric). unfortunately, these don't provide a good variety of smells. anybody know of other OTC alcohols/carboxylic acids? if not, i may have to make some:\

I can't think of any OTC ones at the moment. Perhaps you could get some from your school labs you don't need a large amount to make enough ester to smell it, so they may give you some. If not you may have to "borrow some"

~Scot

Gunpowder can detonate if it is unconfined, if it is above a certain weight in a pile. The weight of the gunpowder sort of confines it.

Dosen't that make it confined?

~Scott

We did this AGES ago in chem and I'll see if i can remeber it.

The CO2 is in equilibrium with dissolved carbonic acid. You want to increase the pressure as the equilbrium will shift to oppose the change and dissolve more gas. The dissolving process is (if memory serves) exothermic so once again if you lower the temperature then it will resist the change and dissolve more gas. So keep it cold and pressurised, thats your best bet.

~Scott

I heard you just have to boil acetic acid with your alcohol and distill the product and theres your ester. Btw, what ester is created between Isopropyl alcohol and acetic acid? iospentenyl acetate?

 

Im just guessing by the "iso" prefix.

Thats the basic procedure but its a bit more delecate then that, it also dosen't have to be acetic acid it can be and carboxyl group.

As for the name it all depends what system you use there are often many 'correct' names for the same organic compound but the one you've used is fine it implies the structure and is chemically correct. However I mostly use ethanoic instead of acetic, its just personal preference and what you (or your markers) understand the best.

~Scott

BenSon brand Home remedy for itchy and red mosquito bites :

Now this will sound a bit wierd but just hear me out. Spit on the bite then punch it(hard) a few times. (rinse and repeat as necessary ) Strange I know but it does work.

~Scott

Try making some esters they are not particularly hard and is a good beginner experiment in orgo. Have patience though its not the speediest of reactions, but quite satisfying. Also avoid esters that use butanoic acid they aren't harder to make but the smell of the acid is definately one to do under a fume hood.

~Scott

Sorry Dak I can't read german

~Scott

I also broke my pinkiy just above the knuckle. Thought years ago, once they strap it it dosen't hurt as much, I can't remember how long it took to heal thought. It sticks out at a bit of an odd angle still when my hands are limp, but its not like i can't make a fist or anything.

~Scott

Niether can any of the Noble gases.

Incorrect, I'm sure google can help you with this one.

~Scott