hermanntrude

I have to write a 2000 word essay due tom on this question. It is for a Uni foundation unit and the topic is completely unrelated to my study course (yes I do think that it is pointless).

Someone will probably help you out a bit. The physicists here are very knowledgeable, but you didn't give them a LOT of time, did you?

I wanted to respond to this because your attitude needs a little adjustment. Don't get me wrong, i mean no offence, i'm a chemistry instructor and I often encounter this sort of thing.

Perhaps the best way to show the error in your thinking is to make a suggestion:

If you feel this topic is pointless, don't do it. See what happens.

Now you know what will happen, of course. You'll fail. So at the very least, the topic has ONE point: to get you through this course. However you might even be wrong about it being totally unrelated. Most fields are related to each other in some way.

Either give up your course or learn to love it.

is this book written with the intention of publishing for free, or is this a copyright violation that you're trying to involve SFN in?

Could be CL ?

please read the thread before replying to it.

Thank you all for answers! Everything makes so much more sense now.

 

Just curious, UC mentioned that ideal gas considers cases like low pressure and high temperature. I agree with the low pressure, but how does high temperature fit in this case as well? Or is it just a direct application of Charles's Law?

at a high temperature, the molecules have more kinetic energy, which makes any attractions between the molecules less significant when compared to that kinetic energy. Think of two people running past each other, and one tries to grab the other. The faster the people are running, the less effect the grab will have.

yes well the charge is really on the nitrogen it's on the whole NH4 unit. This type of species is called a polyatomic ion. it's a small molecule with a charge on it.

there is a positive charge on the nitrogen because it has given up one of its electrons, to a hydrogen atom. If any atom loses electrons it becomes positively charged.

i didn't think of that. Nice explanation

Hi zaindapain,

 

Well,Is Science important? The answer lies right in front of our eyes. Think about a world without technology. No computers, no cars. No vaccines or cures for diseases. Life would be joyless and extremely hard....

Actually, you might be wrong there. It's been shown (according to hearsay, admittedly, but hearsay from qualified psychology instructors) that the experience of joy and sadness are relative. That is to say that the highest heights of joy can only truly be experienced and/or appreciated by those who have experienced the deepest depths of misery and pain. Without suffering there is no true joy. this is why many young people in rich neighborhoods tend to experience a joyless, unenriched, listless sort of life, until they do something crazy like go and volunteer in a third world country or even just get a job.

Perhaps a world without technology, then would allow humans to experience joy more fully, and appreciate it in a deeper manner.

Perhaps again, despair and emotional pain are always available to us in large enough quantities for us to experience joy properly, despite technology making some things easier for us.

Either way, I wouldn't turn back the clock. I love science, I love knowledge and any suggestion we should abandon it for what we used to have seems absurd to me. However, perhaps we could spend a little more time working on how to use science and technology in a better, more friendly way.

i'm not sure of the exact reaction but I wouldnt be surprised if it did indeed oxidise the rubber, and by doing so, be reduced itself. probably to MnO2 and some potassium salt. I'm just guessing, though.

acetone and water are miscible (they do mix). However I guess it's possible you put it in quite gently and without stirring, in which case one might float on top of the other.

Molten lye means hot concnetrated NaOH solution(>30% if from membrane cell or >50% if produced from Mercury cell). It attacks pyrex glass, even MS tanks. container made of Nickel and INCONEL can be used for handling caustic lye

molten lye means liquid sodium hydroxide (not aqueous). The question has already been answered anyway. Please read a thread before responding to it.

assuming your initial statement is true (that gluten is a problem only if it isn't broken down into it's component amino acids) it should be possible to do. hydrolysing proteins is usually simple enough... although perhaps there's something special about gluten?

this is a good point, although there are more. compounds like these.

Perhaps it's better to leave it at something more general, like "don't mess with chemistry unless you know what you're doing"

the usual reason for filtering something is to remove any solids. Without more details it's hard to tell in this particular example.

KMnO4 is a strong oxidiser. what do you think it might do to rubber? and what do you think that might do to the KMnO4?

dr syntax is perhaps being a bit heavy-handed with his words but he does have a point, jordehwa. You can't do chemistry by just randomly choosing some random chemicals and then subjecting them to a random procedure. Most of the time nothing very interesting will happen, sometimes something interesting will happen but you won't have a clue what it was and every now and then, something will kill or hurt you.

Please plan your experiments first and be prepared for safety issues that might come up.

try this, if you can...

http://81.207.88.128/science/chem/exps/lead_electrolysis/index.html

Pay very careful attention to the safety guidelines... lead is very unhealthy stuff

As far as I know the process you described would result in chlorine [ a very poisonous element ] collecting around the positive electrode and sodium [ a very reactive metal ]collecting around the the negative electrode.

you'll never make sodium by electrolysis of an aqueous solution. Don't worry about that (read my thread on "no you CAN'T make sodium!"). However if he was using iodised salt, it could be a touch of iodine dissolved in the water, perhaps? certainly he'll be making chlorine, and he's already been warned about that.

I note that proteins don't rely on carbon forming long chains. I'd imagine that at lower temperatures a silicon based analogue might be possible. Also let's not forget that the presence of oxygen seems to be important for higher life forms... perhaps that's part of the deal...

read the thread "how to purchase chemicals" or something like that. it's not hard to find it's near the top because people keep necromancing it

thanks guys. I'm sure that guy who asked the question 4 years ago is delighted to have a "full" answer. In actual fact most courses only ask you to know that there is a special stability associated with half-filled and full subshells, not why.

the easiest way to do this, i suspect, will be to make a very small wind tunnel. the smaller the diameter of the wind tunnel, the faster you can make the wind blow. Use whatever fan you can get and funnel it down to a small tunnel.

what are you intending for it to lift? and how will you measure it?

the reference book is a great thing and i agree with you that it's sensible to provide such books to students. nevertheless, this is the situation we're in. it is a disease of north america whereby people confuse knowledge and memorisation with intelligence

in fact phosphoric acid is a weak acid in all three ionisations. The first is a fairly strong weak acid but it's still considered weak. It's Ka (Ka1) is 7.1 x 10^-3.

you can make oxygen free radicals from oxygen gas if you shine UV light on it, i think. eventually it forms ozone