Ok, this question is an IChO preparatory problem, 2008, a very nice one indeed.
This is only an extract from the original question.
Please try to read the entire question, it is a beautiful one.
This is the part i have doubts in. Here goes:
...’It is far better to keep the contents in mineral oil,’ Holmes explained and showed me a bottle. ’This will keep it safe from air but also makes it more flammable.’
The yellowish liquid in the bottle covered a few thumb-sized pellets.
’Is this a dangerous poison?’ I asked.
’Not at all, Watson. Have you ever seen a poison in so big a pellet? It would hardly be healthy to swallow, but that is not the point. Now look at this.’
He took out a pellet, dried it with great care, and dropped it into a bowl of water. Instead of slowly dissolving or sinking, the pellet began a strange dance on the surface of the water, hissed ominously, gave out bubbles and some malodorous product. The acrid fumes took me by the throat and set me coughing.
’Holmes, this will kill us both,’ I screamed.
’You should have seen the reaction with hydrochloric acid. Anyway, I told you it is not particularly poisonous,’ said Holmes coughing. With dramatic suddenness he struck a match, and as he held the match nearer, the bubbles caught fire and gleamed with the most beautiful crimson flame I have ever seen.
’Magnificent, is it not? One ounce of this substance when reacting with water or hydrochloric acid gives more than three cubic feet of gas. To be precise, 3.068 cubic feet at 80.0 degrees and atmospheric pressure.’
’You measured this?’ I cried.
’Of course I measured it,’ said Holmes with an impatient gesture. He took a small bottle labelled phenolphthalein and put a few drops of its contents into the bowl of water, which turned pink immediately, its colour resembling the gleam of the flames.
’Is this why this substance is so precious?’
I tried to solve the question and from this part of the question i have posted, i have come to the conclusion that the pellets are LiH.
First, i tried to do the calculation bit, and then i tried to substitute certain compounds which i thought would fit the bill. This, i guessed using some 'chemical intuition'.
perfectly agrees with the values...yippee!!!
The eqn that i obtained is thus:
My doubts arouse from this point onwards:
What is that malodorous product given in the question?
- It's certainly not Hydrogen gas , as it is odourless. I don't know about LiOH...
What are those acrid fumes?
-Again, it can't be hydrogen...
and What about the bubbles?What are they, and why do they burn with a crimson flame? Does it have anything to do with the flame test for Li???
Please help me out!!
Note : Temperature in Fahrenheit.