John Cuthber

The simplistic answer is that it's easy; you ask the person if they wish to continue to live.

If they are in a position to answer that then it's easy, you respect their wishes. (no matter what the cost; remember that it might be you next time)

The problem arises when someone else has to make the decision because the person concerned is no longer able to do so.

I don't know the answer (in fact I don't think there is "an answer" ) but it makes things a lot easier if you talk to those who might be left in the position of having to make that choice while you still can and explain that , as far as you are currently able to judge, you wouldn't (for example) wish to continue if the spice girls disbanded or if you had no realistic prospect of being able to inform the world of your opinion.

Sorry, I seem to have missed something.

Please could someone explain to me why someone's sexual preferences should be correlated ( positively or negatively) with, for example, their desire to defend their country's interests?

I also don't understand why it would make a difference to their effectiveness as a member of the armed forces, but perhaps that's just me. I wasn't aware that battles generally stopped if one of the people involved wished to sleep with one of the others.

The question of whether or not military action is in the interest of their country is another matter.

Sounds like a septum seal (or a very small "iris port")

Wiki gives a pKa of 2.47

Since it changes colour there's something going on; deprotonation seems a good bet.

This base is an acid.

You could try bubbling oxygen gas through it and try and oxidise the carbon to carbon dioxide....that might work....but I guess you'd also run the risk of oxidising the manganese too...

Just how often do you normally see oxygen attacking carbon under normal conditions?

It would work if you heated it (about red hot, like a coal fire, would do it) but the MnO2 would decompose.

Air won't oxidise Mn further than Mn(IV) except under strongly alkaline conditions.

Homeopathy is total nonsense; then again, so were many "therapies" at that time.

Since it was a lot less dangerous than, for example, blood letting or purging, Hahnemann's patients were probably better off than most.

Now we know better and we should dump homeopathy along with the other bogus treatments.

(I await a meta analysis that shows that homeopathy only works for Scorpios)

For a minute lets assume that these are facts

"lets look at the facts:

Water is at least 50% more potent a greenhouse gas than CO2

Over 80% of global warming is caused by water in the atmosphere

Humans are resonsible for about 2% of all CO2 emmisions each year."

So what?

The fact that you post this indicates that you haven't thought it through.

Water is a potent greenhouse gas.

True enough but it's more or less stable.

It's like saying that in cold weather you need a quilt so putting on another blanket won't make you warmer because the blanket is thinner than the quilt.

Don't you realise that the effect is (at least) additive?

Much of the earth's warming is due to water.

True enough, but the same argument applies, the CO2 still adds to it.

There are also complications due to saturation effects.

There's so much water in the atmosphere that, whatever wavelengths of IR are absorbed by water just about don't make it through the atmosphere. Only a tiny fraction of that radiation gets through.

Adding a bit more or less will not make much difference because it can only affect that tiny fraction.

Humans are only responsible for a small faction of the CO2 emissions.

Fair enough- but we are responsible for practically no removal of CO2. so, unlike the rest of the system (trees, volcanoes, subduction, whatever) we continuously push the CO2 concentration upwards.

Incidentally, re. that graph; even if the curve is flattening out, it's flattening out at a higher temperature than any before it on that record.

An old joke, but it illustrates the point.

Did you hear about the homeopath who forgot to take their pills?

They died of an overdose.

Ist the word you are looking for "synergistic"?

Pure oxygen is toxic to humans and I guess it would be for spiders too. At the least it will affect their metabolism.

It would be easier to use something like an aquarium pump to drive air through soda lime into the tank and then let the air flow out of the tank through lime-water.

You could titrate the carbonate formed if you wanted to make it quantitative.

I suspect the problem will be that a tarantula simply doesn't make much CO2 so it will be difficult to measure. There's also a problem that if you have anything else alive (like the spider's food) in the tank then it will mess up the measurement.

All this talk of what's the best drying agent isn't really important here. You are trying to remove bulk water so even table salt will do as a desiccant.

As has been pointed out a number of times the NaClO isn't stable so you will lose a lot of it no matter how you try to dry it. You certainly won't end up with a pure solid.

"Actually for staying power as a desiccant, conc sulphuric is tops in terms of g/g water capture. "

Actually it's not. Both sodium and magnesium sulphates will absorb roughly their own weight in water before they are exhausted. 50% sulphuric acid isn't much of a drying agent.

The question of whether sulphuric acid is more of a hazard than P2O5 isn't relevant here. You don't need to use either. The reason I mentioned it was simply to illustrate that your assertion that "Conc sulphuric acid has an affinity for water that is unmatched." isn't correct. I could have chosen a number of other desiccants like sodium wire. All strong dehydrating agents are dangerous because we are mainly water.

To see any appreciable fizz from baking powder or soda, the water must be acidic. Otherwise, what is the reaction that will lead to Na2CO3, or NaHCO3 forming CO2 gas?

Baking powder (rather than soda) contains an acid (classically cream of tartar, but others get used).

On heating bicarbonates are converted to carbonates and CO2 and water.

2NaHCO3 --> Na2CO3 +H2O +CO2

2500 Calories a day is, according to Google, about 120W.

Most of the energy we consume gets converted to heat so, under typical conditions, we use about 120W keeping ourselves warm.

"Conc sulphuric acid has an affinity for water that is unmatched."

Phosphorus pentoxide will strip the water out of concentrated sulphuric acid and convert it to sulphur trioxide.

Most people find it cheaper and more convenient to regenerate desiccants like silica gel in an oven.

Incidentally, as soon as the acid picks up any water it stops being nearly as good a desiccant.

Other drying agents can pick up more moisture without losing so much of their power so, even if H2SO4 was quicker at first it may lose ground in the end.

If you want to speed things up use a vacuum desiccator. Also it's not generally a good idea to use sulphuric acid as a drying agent because it's rather nasty stuff to work with.

Estimates seem to vary but it seems that you can see someone strike a match from about 10 miles away (on a clear dark night)

Even a poor job at collimating that would let you see it from further away. People use simple searchlights to shine on to the clouds to attract attention to events.

IIRC the first synthesis of the perbromate ion was by radioactive (beta) decay of a radioisotope of selenium as a selenate.

The yield was lousy, but they did make the stuff.

When radioactive decay occurs in the body it's not just the molecule containing the decayed atom that gets damaged. The radiation trashes a bunch of nearby molecules too.

Odd; did the baking powder have a "best before" date on it?

The whole purpose of the stuff is to fizz (slowly) when added to water-containing foods.

Incidentally, baking soda will fizz in very hot water but that might not help you much.

I think the dull answer might be to do with this.

http://en.wikipedia.org/wiki/Regression_toward_the_mean

You might tell your friend to search for

"ginger beer recipe"

It's likely to make a better product.

Since vitamin C is very soluble in water there's nothing much to gain by using a base to extract it. Also, it is less likely to be oxidised by the air if it is in neutral or acid solution.

(BTW, a lot of the column manufacturers supply "application notes" for their columns. It's blatant advertising, but it's a good way to find out about analytical methods, on-line, for free.)

What do you know about the ratios of G, A and C in "earthly" DNA?

What's is different on Mars and how might you explain that?

There is a potential problem with local anaesthetics- they get absorbed through the large open wounds and they are rather toxic if you get a lot of them.

I'd still like to know why the baking powder didn't work.

Do you know it's different from baking soda?

"The conc acid will remove water quicker than normal desiccants"

When the water leaves the solution, how does it know to hurry up because there's some sulphuric acid out there?

I suspect that there are a very large number of possible answers to the question.

For example, you could put the two items down and go off and do some vital research that gets you a Nobel prize.

Or you could put them down and vegetate in front of the tv.

or, well lots of things really.