Chemistry - January 2007

I grind my coffee beans just before brewing, to a fine powder. I use the drip method, with hot water poured over the coffee in a filter in a cone. When I take the cone off the pot after brewing and set it aside, some of the cooling grounds reconstitute themselves into beans again, complete with ridge.

What kind of molecular magic is happening here?

(And no, no beans are left unground when I put them in the filter. And no, I am not delusional. This has happened many times.

2007-01-30 10:08:15 · 2 answers · asked by dude242 1

2007-01-30 10:00:06 · 2 answers · asked by jackie g 1

2007-01-30 09:52:57 · 1 answers · asked by danity0414 2

2007-01-30 09:47:41 · 4 answers · asked by Tracey Lee ♥ 2

2007-01-30 09:46:16 · 4 answers · asked by Thank you 1

1. What is an example of thermal energy?
(ex. an example of kinetic energy would be a bouncing ball)
2. How is chemical energy related to chemical change?

2007-01-30 09:40:17 · 4 answers · asked by * 2

My oldest daughter is doing a science project on the effects of sodium cyanide on bronze and other metal, she only needs a small amount to show the effect but I can not find this stuff anywhere. I have checked jewlers and craft stores to no avail.

2007-01-30 09:37:02 · 2 answers · asked by flawolfchild 2

2007-01-30 09:32:22 · 2 answers · asked by danity0414 2

I need to know for a test!

2007-01-30 09:27:16 · 16 answers · asked by ♥star.light 2

If you have 1 L of ethanol and you put in in a room that is 3 m long, 2.5 m wide, and 2.5 meters high, will all of the alcohol evaporate? And, if some liquid remains, how much will there be?

I already found that the vapor pressure of ethanol is 59mm Hg at 25 degrees C, and at this temperature, the density of ethanol is .785 g/cm^3.

2007-01-30 09:25:00 · 1 answers · asked by Christie 3

and no this is not my homework...lol :P

2007-01-30 09:05:56 · 1 answers · asked by Tracey Lee ♥ 2

And is it polar?

2007-01-30 09:01:50 · 4 answers · asked by Rita135 2

I'm going to ask this one more time because I didn't get an answer....Based on dispersion forces, dipole-dipole, and other intermolecular interactions, how come BeO's melting point is so much higher than BaSO4?

2007-01-30 08:56:05 · 2 answers · asked by Anonymous

If the density of a 40% mass solution of ethylene glycol in water is 1.0514 g/mL, at 20 degrees C, what is the molarity?

Ok, so I researched and found that ethylene glycol is C2H6O2, which when I calculated, resulted in a molar mass of approximately, 62.08g/mol.

Now, should I multiply

62.08g/mol x 1.0514 g/ml x 1000ml/1L x .4

I think I am approaching this incorrectly...any ideas what I am doing wrong?

2007-01-30 08:34:41 · 2 answers · asked by Anonymous

AlCl3(aq) + 4NaOH(aq) → NaAlO2 (aq) + 3NaCl(aq) +2H2O(l)?

Also how did you derive at this answer?
Are there conversion factors involved?

2007-01-30 08:29:57 · 3 answers · asked by San Fran Kid 2

Ok, so I have to come up with a procedure for a lab that i have to do tomorrow. in this lab, i have to find the following: (for 10ml. of water)
1. Mass
2. How many moles
3. The number of molecules.

So, I think i have part 1. to find the mass which would be: to measure an empty graduated cylinder, fill it with 10 ml. of water, and measure it then, then subtract to find mass.

But, after that I comprehend very little on what to do with the rest.
Part 2, i thought I was told i would have to use the mass, but, i have no idea how to do it, and also how to find out how many moles.
and part three, I have no idea
So, my question would be, can you verify that Part one is the correct way to do it, and please help me with parts two and three. thanks.

2007-01-30 08:19:35 · 5 answers · asked by nicolemoose91 2

Avogadro's number is equal to 6.0221 x 10^23. How many potassium ions are in 5.00g of potassium sulfate?

2007-01-30 08:03:02 · 3 answers · asked by Tracey Lee ♥ 2

My brother wants to know...

2007-01-30 07:55:40 · 6 answers · asked by Anonymous

2007-01-30 07:45:39 · 3 answers · asked by Anonymous

I need the answers to these questions

1. Where would you expect to find the electrons of an atom with an atomic number of 7?

2. How do covalent bonds differ from Ionic bond?

3.Nails are formed from molten iron. Nails made of iron can rust after exposure to water and air. Which of these changes is an example of a physical change?

2007-01-30 07:20:43 · 9 answers · asked by Anonymous

Different types of oil used in saponification can cause varying hardness in the soap. Why is this so?

2007-01-30 07:09:50 · 1 answers · asked by Just Somebody 2

2007-01-30 06:58:59 · 3 answers · asked by theskyisthelimit02 3

2007-01-30 06:56:52 · 2 answers · asked by Jared H 1

Prior to performing a titration, three drops of phenolphthalein were added to 15.0mL of a tartaric acid solution. The solution was then titrated to the end point with 24.5 mL of 0.2297 M NaOH. What was the molarity of the tartaric aid solution?
I don't want just an answer please... I need to know how to do it!]
Thanks.

2007-01-30 06:53:36 · 2 answers · asked by woventemple 1

is it possible to determine the percent composition of ethyl alcohol in whisky and why?

is it possible to determine HgO in CuSO4*4H2O

it is possible to determine the percent composition of CaCO3 in KClO3 and why

2007-01-30 06:48:58 · 3 answers · asked by smile 1

Has any1 got any ideas for a small Science experiment that could be done at home or school! Has to be safe and has to have a reason behind it!

2007-01-30 06:47:29 · 8 answers · asked by ♥My Obsession Is You♥ 2

Im 13 in 2nd year and i was doing an experiment to make oxygen with hydrogen peroxide and mangenese dioxide as a catalyst anyway i had to put this thing and there was water in it and (stupidly i cant believe i did it) i sucked the tube and founded it was a strong base! and then my teeth felt wierd ! but before us another class did how to make CO2 and they used hydrochloric acid and it might have been that i ate ! just a few drops ! please help i dont feel good and my teeth feel wierd.

2007-01-30 06:35:04 · 13 answers · asked by ? 2

Wondering if anyone is willing to help me with a few chemistry problems...

2007-01-30 06:23:30 · 5 answers · asked by ScarlettPink 1

Got coursework to do tomorrow and need to watch these videos. Please help!!

2007-01-30 06:15:40 · 1 answers · asked by lykastar 3

2007-01-30 06:09:30 · 1 answers · asked by Netra 1