Chemistry - October 2007

Is every element on the table of Mendeljev already found on Earth, or are there still some undiscovered?

2007-10-25 08:55:10 · 1 answers · asked by JohnyD 3

2007-10-25 08:54:01 · 6 answers · asked by joebeina 1

i know how to do it normally just not this way so help me out :)

2007-10-25 08:45:20 · 4 answers · asked by joebeina 1

2007-10-25 08:40:12 · 2 answers · asked by Kay bay bay 1

1 . the pores in the pot draw the cold inside
2 . the pores allow contact with outside ambiencewhich lowers the temperature
3 . the pores allow water molecules to move back & forth by cooling it down
4 . the pores allow water to evaporate & the heat for this is taken from the pores inside

2007-10-25 07:45:46 · 5 answers · asked by hems 1

Does anyone have a good recipe for polymer clay which can be made from every day materials?

My daughter and I have made "slime" from glue+H2O+borax solution and had a lot of fun playing with it but now we'd like to try our hand at something firmer and bake-able.

Thanks for your ideas!

2007-10-25 07:39:45 · 3 answers · asked by ♪ 4

2007-10-25 07:32:55 · 2 answers · asked by mandi 1

Also can any body advise any web pages i can look at that will tell me things like how it combines why? Molecular and structural formula, at A level.
Thanks

2007-10-25 07:24:42 · 3 answers · asked by Anonymous

Hi guys, I really need help.
So I need find the molecular formula of CuSO4.xH2O.

We used 5.2 g of it, and there was 3.31 g of CuSO4 . With this, I found X to be 5, so, its CuSO4.5H2O

And I found the mass of this to be 250 g. Now how do I get the molecular formula?

Thanks,

-Stan

2007-10-25 07:08:58 · 3 answers · asked by Mike T 1

How many moles of carbon monoxide gas are produced from the reaction of 5 mol of SnO2 (s) with 9 mol of carbon according to the equation below?

SnO2 (s) + 2C (s) --> Sn (s) + 2CO (g)

2007-10-25 07:04:28 · 5 answers · asked by nancy 2

A. hydrochloric acid
B. acetic acid
C. sodium hydroxide
D. ammonia

2007-10-25 06:55:02 · 3 answers · asked by Broken Blue Eyes 6

2007-10-25 06:51:15 · 4 answers · asked by asst3@sbcglobal.net 1

If you are told the purity of compund Z is 85% and the reported value for its molar extinction coefficient is 19,200 M-1cm-1 at 605 nm. What should the molar extinction coefficient of this impure compound Z measure as? Can someone show me how this is done?

2007-10-25 05:48:13 · 1 answers · asked by raleighzia 1

2007-10-25 05:19:56 · 6 answers · asked by bluenose159 1

1) Calculate the frequency associated with light of wavelength 740 nm.

2) Microwaves have frequencies in the range 109 to 1012 /s (cycles per second), equivalent to between 1 gigahertz and 1 terahertz. What is the wavelength (in meters) of microwave radiation whose frequency is 2.157 x 1010 /s ?

2007-10-25 04:48:17 · 2 answers · asked by keya_na 2

They showed on Star Trek one night, fire, which looked like red/yellow molecules floating, bouncing into each other. Is fire a specific molecule?

2007-10-25 04:31:49 · 5 answers · asked by Anonymous

I had a practical on mass spectral fragmentation patterns of some organic compounds and had a table to fill in to show the m/z, formula of ion and fragmentation diagram. I have done that but there is also a calculation to be done but i dont know how to do it. As the teachers are also unavailable and i have to hand this in tomorow i am unable to find out how to do it.
So please anyone who may know or has done this practical before please help and i will very much appreciate it.
when i did this practical i got on the graph for CH2Cl2 there were a total of 13 peaks.
i am only told to calculate the intensity ratio for three peaks.
Thank you
Regards

2007-10-25 04:15:18 · 1 answers · asked by Anonymous

2007-10-25 04:04:01 · 2 answers · asked by Jocelyn W 1

(continued) polar covalent bond

2007-10-25 03:47:13 · 2 answers · asked by kleenexpocketpack 1

During a moon landing, one of the experiments performed was the measurement of the intensity of solar wind. As a collector, an aluminum strip of about 3,000.000 square centimeters was used. It was found that in 100.00 minutes, a mass of 3.00 x 10^-10g of hydrogen was collected. What is the intensity of the solar wind (number of atoms per sq. centimeter per second?).

2007-10-25 03:18:02 · 1 answers · asked by Caramel 2

using spectroscopy

2007-10-25 03:04:23 · 2 answers · asked by sassybrat_018 1

2007-10-25 02:19:24 · 2 answers · asked by CourtneyMT 3

One mole of nitrogen gas confined within a cylinder by a piston is heated from 0°C to 883°C at 1.00 atm.
a) Calculate the work of expansion of the gas in joules (1 J = 9.87 10-3 atm·L). Assume all the energy is used to do work.
b) What would be the temperature change if the gas were heated with the same amount of energy in a container of fixed volume? (Assume the specific heat capacity of N2 is 1.00 J/g·K.)

I've been trying to figure this out all morning...

2007-10-25 02:01:28 · 1 answers · asked by Anonymous

calculate the concentrations of all species in this solution.
[H+] mol/liter
[OH -] mol/liter
[Cl -] mol/liter
[NO-] mol/liter

2007-10-25 01:48:26 · 3 answers · asked by Anonymous

1. Aluminium + Sulfuric acid -> Aluminium sulfate + Hydrogen

2. Copper sulfate + Lead nitrate -> lead sulfate + Copper nitrate

3. Copper + Oxygen -> Copper oxide

can someone please do these questions for me and show answers please! thank you

2007-10-25 01:22:13 · 6 answers · asked by . 4

discoverers name on the periodic table

2007-10-25 00:32:22 · 3 answers · asked by john cover 1

2007-10-24 21:19:51 · 2 answers · asked by ishika m 1

2007-10-24 21:02:49 · 2 answers · asked by ishika m 1

What mass of solid aluminum hydroxide can be produced when 50.0mL of 0.200 Molarity Al(NO3)3 is added to 200.0 mL of 0.100 Molarity KOH?

2007-10-24 19:07:49 · 2 answers · asked by Kennedy 1

of the water sample?

2007-10-24 18:32:55 · 2 answers · asked by Nikoru Y 1