Chemistry - December 2006

2006-12-21 10:25:16 · 5 answers · asked by Anonymous

2006-12-21 10:23:53 · 4 answers · asked by Anonymous

2006-12-21 10:21:57 · 2 answers · asked by Anonymous

I guess I don't understand -- if its so dense and heavy, doesn't that mean the molecules are packed closely together? Then why is it "soft"? I've already read the wikipedia article on lead, and it hasn't answered this question -- so I leave it to the resident chemists to explain!

2006-12-21 10:19:50 · 7 answers · asked by Sara 3

2006-12-21 09:39:48 · 7 answers · asked by fffffffff r 1

Water and Ammonium Acetate?

2006-12-21 08:45:29 · 5 answers · asked by ♥ 6

A light detector based on the photoelectric effect is made with cesium metal. Cesium metal has a work function of 3.4 times 10 raised to the -19th J. What is the longest wavelength of light that one could expect to detect with this device?

a) 850 nm
b) 580 nm
c)1700 km
d) 7100 km
e 420 nm

Please show appropriate work. Thanks.

2006-12-21 08:41:49 · 2 answers · asked by Anitec 2

what neutral substance could be formed from the combination of the H+ ion from the acid and the OH- ion from the base?

2006-12-21 08:35:03 · 6 answers · asked by ♥ 6

2006-12-21 08:13:09 · 7 answers · asked by The Question Man 2

2006-12-21 08:04:52 · 7 answers · asked by Jeffrey 1

Given information.
1 eV = 1.602 x 10 raised to the -19th power J
1 J = 1 kg m-squared over s-squared

2006-12-21 07:55:08 · 4 answers · asked by Anitec 2

2006-12-21 07:17:33 · 7 answers · asked by Molly 1

Sometimes I get a sample of a white pigment that might be either TiO2, BaSO4, ar a mixture of both. I'd like to know what the pigment is. Any quick and dirty qualitative tests I can do to detect Ba, Ti, or these oxides?


Unfortunately I do not have access to any scientific equipment such as spectros, electron microscopes, light microscopes, etc. I do have a blowtorch and some beakers.


Now I'm remembering something from my chemistry set days that you could make a bead of material, burn it in a torch flame, and tell what it is by the color of the flame. Help?

2006-12-21 06:44:00 · 2 answers · asked by Anonymous

It isn't diamonds.

2006-12-21 06:29:26 · 4 answers · asked by Steve C 7

a.) 3,4 diethylheptane
b.) 4-isopropyl-3- methyldecane

2006-12-21 06:07:07 · 4 answers · asked by babycakez 3

How many litres of solutions A and B should be mixed to make 100 litres of 14% syrup

2006-12-21 05:31:37 · 3 answers · asked by KIMBA 1

A compound contains 12.8% Carbon, 2.10% Hydrogen, 85.1% Bromine (by mass) Calculate the empirical forumla of this compound. If the molar mass of tehis comopound is 188 g/mole, what is teh molecular formula

For teh empirical forumla would i just find the ratios of all those elements by doing C/H and Br/C??
For teh molecular forumla, I have no idea how to do it

2006-12-21 05:28:54 · 5 answers · asked by silentcargo 3

Two isotopes of Boron occur in nature. Boron-10 has a mass of 10.013 amu and an abundance of 19.61%. Boron-11 has an abundance of 80.39%. The molar mass of a natural sample of boron is 10.811 g/mol. What is the mass of a boron-11 atom?

Please show how work is done (and no this is not homework, this is review for my final). Thanks.

2006-12-21 05:14:53 · 4 answers · asked by Anitec 2

what is coals elemenal composition

2006-12-21 04:51:45 · 4 answers · asked by crackg 1

Would an equal number of sodium chloride, NaCl, or calcium chloride, CaCl2, do a better job of keeping streets from freezing? Explain at a molecular level. Why do most highway departments use both chemicals?

2006-12-21 04:50:13 · 4 answers · asked by luc_allmon 2

The Alkalinity or acid of a substance ie. Soil is measured in pH.
Neutral is a pH of 7. Beneath that figure the substance is acid and above 7 it is alkaline

2006-12-21 04:45:33 · 4 answers · asked by Ronald N 1

what is the elemental composition of coal(what elements make up a specific fuel)?

2006-12-21 04:35:29 · 6 answers · asked by crackg 1

2006-12-21 03:14:40 · 4 answers · asked by tomi 1

2006-12-21 02:54:32 · 3 answers · asked by anushree 2

i wanna know if there are some sites in which we can get the past papers for chemistry.I want the structured questions and mainly the multiple choice questions.
i have my test after tomorow on ''states of matter'' and ''chemical energetics''

thanx in advance

2006-12-21 02:36:35 · 3 answers · asked by mk137 1

2006-12-21 02:26:11 · 4 answers · asked by francis 1

hello ,
i want an example of drug developed via genomics or cloning or Polymerase Chain Reaction (PCR) or Proteomics or Molecular modeling or Peptidomimetics or Glycobiology

2006-12-21 02:19:40 · 3 answers · asked by Nawari 1

2006-12-21 01:44:51 · 2 answers · asked by racingfreak66 1

Liquid petroleum gas means, is it in the gasious form or in liquid form at the atmospheric temperature and pressure? All gases are alkanes(mojor part of this is butane) and these are in gasious state only, bacause they are not higher alkanes.

2006-12-21 01:24:20 · 5 answers · asked by sara_swathi m 1

I'm a bit stuck at this - can anyone help please!
The question is;

At 320C, the rate constant for the 1st order reaction

SO2Cl2 ---> SO2 + Cl2

is k=2.2 x 10^-5 s-1.

What percentage of SO2Cl2 will decompose in 90 minutes?

I know that to work out the half life it is;

t1/2 = 0.693/k

but how do I then calculate the percentage in 90 mins?

Thanks to anyone who can help!

2006-12-21 01:24:03 · 1 answers · asked by Showaddywaddy 5