hermanntrude

i meant you could write the equation, perhaps for the formation of P4O10 from P4 and H20 and calculate deltaG from the deltaS and deltaH, which can be calculated from heats of formation and entropies. however, your method seems to have paid off quicker... assuming of course that the patent has any validity

you could probably calculate whether the reaction is spontaneous using some empirical data from a textbook. perhaps P4 can take the oxygen from water to form P4O10? do you know the calculation for deltaG?

John is correct. Apologies for confusing the issue

You have to remember that the unit cell isn't a discrete entity. it continues more or less indefinitely.

Look at the central oxygen atom. How many Cd atoms surround it? I'll give you a clue: it's more than 4. Also check your answer for Cd.

I'm a bit confused about the second question, since there are 13 oxygen atoms and 14 cadmium atoms, but you were correct in saying that the empirical formula is CdO. It might just be that 14:13 is so close to 1:1 that you're expected to round off to 1:1.

to be able to answer question 3 you will need to know something about the dimensions of the unit cell.

hipolito, read the rules about homework help. Also read the forum rules. Don't duplicate your posts, and at least try to do some of the work in your answer. For a question like this it's hard for us to help you unless you tell us at least what you're thinking for the answer.

I'm a pure chemist, and I think chemical engineering is a wise choice if you can handle all the physics and math involved. There are a dozen chemical engineer jobs for every one chemist job.

As for taking chemistry online I'd say it's not impossible but it will be harder for you this way. It takes a lot of motivation to study onoine to a reasonable standard, and it's quite frustrating being "taught" by a guy who sends an email once a week and expects you to do the rest for yourself.

when a reaction occurs, the new product isn't always more stable than the reactants.

EDIT: the question is answered above. It's better than my answer by a long way

the decompositions it's talking about for the monohydrate and decahydrates are their losses of water:

[ce]Na2CO3.H2O(s) -> H2O(g) + Na2CO3(s)[/ce]

[ce]Na2CO3.10H2O(s) -> 10H2O(g) + Na2CO3(s)[/ce]

In the latter example, probably the sodium carbonate dissolves in its own water as it decomposes. Also it might not lose all ten waters, depending on temperature, pressure etc.

A volatile solid, which sublimes at room temperature, this compound has a characteristic odour similar to that of ozone. It is used widely in organic synthesis, and as a staining agent. It was also used to confirm the structure of buckminsterfullerene.

lignin?

yes. exactly. heat it and it will give off carbon dioxide. But it's quite stable up to about 1000°C. Bicarbonate is much easier to decompose.

with an empirical formula of [ce]C2H[/ce], this molecule is highly reactive. It has been identified in the atmosphere of titan and in some interstellar clouds. it is closely related to the monomer for rubber making.

mercury?

Hydroquinone?

 

correct.

I think humans are unable to know what the subatomic world is really like. It's called the uncertainty principle.

hehe i like it too.

for monatomic ions (ions made of a single charged atom), metals are positive and non-metals are negative (nearly always... there are a few exceptions but they ignore them at you level of chemistry).

For polyatomic ions (things like [ce]NO3-[/ce] for instance which contain multiple covalently bonded atoms but only one charge) you'll have to memorise them. However if you only need to know whether they're negative or positive, negative is the best bet since there are only two commonly cited positive polyatomic ions ([ce]NH4+[/ce] and [ce]Hg2^2+[/ce]).

hi cool video, what was the last thing.

Al + FeO? I just understood something with very hot iron...

Or could someone clarify this for me, the reaction and it's reactants?

 

thx

google "thermite"

A water soluble reducing agent, I am commonly used to reduce silver halides to silver metal. I am also used in skin whitening and in entomological defense systems.

the general gist is that you shouldn't mix things with bleach. it's very reactive and many of its reactions will liberate dangerous fumes.

thalidamide

thermite was definitely the way to go. It nicely made thoughts of firework night and halloween mix together.

I too have a very small youtube channel. If you're remotely interested, check it out. http://www.youtube.com/hermanntrude Any suggestions will probably be cheerfully ignored in the full knowledge that I can't be bothered to change anything :0)

i'm a big fan.