Chemistry - September 2007

a 1.500g sample of a mixture containg only Cu2O and CuO was treated with hydrogen to produce 1.252g pure copper metal. calculate the percentage composition of the mixture

2007-09-11 16:00:10 · 2 answers · asked by abchawaiixyz 1

10ml of Methanol is added to dry sand. The mixture was stirred until no more bubbling occur and the sand look uniformly wet.

Does this indicate that the dry sand and methanol are reacting?

I'm guessing yes, but is this a trick question?

2007-09-11 15:56:18 · 5 answers · asked by Nhat t 1

I had no idea it would be so hard to find a jar (or bottle I guess) online. Can somebody help? It has to be amber colored glass and contain 2-5 liters AND have a lid. Any help is appreciated.

2007-09-11 15:42:37 · 2 answers · asked by BunnuvaSitch 7

balance the following two only
1)K(s) + H2O(l) ----> KOH(aq) + H2(g)
2) Al(s) + Fe2O3(s) -----> Al2O3 + Fe(s)

could you please balance and classify the next four equations..thanks a bunch!

1) ___P+ ___O2 -----> ____PO3
2)___Al + ___H2C03----> Al2(CO3)3 + ____H2
3)___NaClO3+____-----> NaCl + ___O2
4)____Ag2SO4 +____AlCl3----> ___AgCl + ___Al2(SO4)3

2007-09-11 15:38:14 · 2 answers · asked by daniel n 1

Find the molority

there is 15 grams of Potassium Nitrate in 2 Liters of water.


and i got 9.6M is this right?

2007-09-11 15:31:54 · 3 answers · asked by Anonymous

I need to do the work for Chemistry class, and I am completly lost.

So far ive done : 450 m/s= (1 min/60 sec) (1hr/60 min)

The two "sec" cross out and the two "min."


Then I got stuck.

thanks!

2007-09-11 15:18:02 · 5 answers · asked by freedom.peace_love 1

Aluminum metal reacts with sulfuric acide to form a gas and a salt.

2007-09-11 14:42:45 · 2 answers · asked by blue 1

was plastic made for greater good or like discovery or was it for the worse scince its not biodegadable and its poluting our world?

2007-09-11 14:37:37 · 4 answers · asked by Anonymous

Which measurement is expressed to 4 significant figures?
1 0.00423 kg
24.049 cm
1300 K
82,306 m
62.40 g



Question 2
A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the temperature of the measurement.)
1.992 g/cm3
1.840 g/cm3
1.729 g/cm3
1.598 g/cm3
0.543 g/cm3



Question 3
A dose of medication was prescribed to be 35 microliters. Which of the following expresses that volume in centiliters?
3.5 × 105 cL
3.5 × 104 cL
3.5 cL
3.5 × 10-4 cL
3.5 × 10-3 cL

2007-09-11 14:32:23 · 2 answers · asked by Anonymous

why is it chemical or physical?

2007-09-11 14:29:22 · 3 answers · asked by tha_chosen_one15 2

How much of each of the following substances would you add to water to prepare 1.90 L of a 0.50 M solution?

NiCl2 from the salt NiCl2·6 H2O

I got two answers, and don't know which one is right. Using sig figs, i got

1.2E2 or 2.3E2... which one's correct?

2007-09-11 14:20:34 · 1 answers · asked by Megan 1

How do you do this with unit analysis?

2007-09-11 14:17:34 · 2 answers · asked by Anonymous

2007-09-11 14:12:58 · 4 answers · asked by Mags 2

a) copper metal can be bent into different shapes

b) a steel blade can scratch glass

c) alcohol boils at 60 degrees Celsius


All info welcome

2007-09-11 14:06:24 · 2 answers · asked by shiny 1

we heated a hydrated salt in a crucible with the lid on and the water was supposed to evaporate out.

2007-09-11 14:05:23 · 4 answers · asked by ylai 2

what's the volume of a 2.80g silver ring? (Ag is silver)

2007-09-11 14:00:31 · 2 answers · asked by Anonymous

i just cant figure it out, please help.

Fe2O3 + Br2 --> FeBr3 + O2

and do i have it right? im not 100% sure about the subscripts.

2007-09-11 13:56:39 · 1 answers · asked by ......//;' 4

what property of these metals would allow such a separation!?

2007-09-11 13:45:14 · 9 answers · asked by ♥♥♥♥♥ 1

2007-09-11 13:26:13 · 1 answers · asked by annhall90 1

isn't it 2.702?

2007-09-11 13:25:31 · 2 answers · asked by Anonymous

2007-09-11 13:21:21 · 3 answers · asked by Anonymous

Neon, has three different isotopes. 90.51% of neon atoms have a mass of 19.992 amu. 0.27% of neon atoms have a mass of 20.994 amu. 9.22% of neon atoms have a mass of 21.991 amu. What is the adverage atomic mass of neon. and how did you get that.

my answer: 20.992 amu. is it correct?

2007-09-11 13:20:12 · 3 answers · asked by nothinbutnet2009 4

"The absorption spectrum of a hydrogen atom contains dark bands at specific wavelengths. The emissions spectrum of a hydrogen atoms contains bright bands at the same wavelengths"
Explain why.
HELP ME! :gonk:

Another question asked was, "Contrast the properties of diamagnetism and paramagnetism, give z examples of each. Is a lone germanium atom paramagnetic or diamagnetic

2007-09-11 13:18:06 · 1 answers · asked by Anonymous

Is the formula: C4+H10 correct for Butane? and if so what does H10 stand for? like what chemical?

If thats not right what is the chemical formula for Butane and what do its elements stand for?

2007-09-11 13:08:30 · 4 answers · asked by diamond 4

what is the oxidation number of the metal ion in
1. MnF3

2. Hg2Cl2

please explain

2007-09-11 13:04:24 · 1 answers · asked by PiNk-PrInCeSs 3

what do vinegar and cola have in common as acids?

2007-09-11 12:35:10 · 1 answers · asked by Anonymous

Hi All
Below is an article I found on Yahoo. (scroll below what I wrote if the link doen't work: http://green.yahoo.com/index.php?q=node/1570 )
It's a facinating concept I think. I have little doubt this process will be exploited at some time in the future. One thing bothers me: Once the water is burned, what will the exhaust product be? Will the water naturally reform just as fast as it was consumed? I know there is a LOT of water in the world, but if the water burned as fuel cannot be reclaimed, it's just a matter of time til things dry up permanently.
This process could sell like hotcakes. The "oil burden" would be over. Possibly the dirty exhaust would be over too. This is good. In order for this to be a harmless solution, though, there needs to be a complete cycle: salt water--> energy + exhaust --> saltwater again.
Another consideration is: Can the neccisary radio frequency be produced with enough power in close proximity to life without screwing up that life (us included!) I work with radio frequency generators and there are warnings all over not to turn on power without the proper precautions. Some radio can scramble or cook your brain. So what frequency is this guy using?
Sorry if I sound like an environmental "wacko". I just love my world, and don't want to see it a dead moon in 10,000 years.

I hope this guy does come up with something good.

Any thoughts?

J



Radio Frequencies Help Burn Salt Water
By David Templeton, Pittsburgh Post-Gazette
Tue, 11 Sep 2007, 11:41AM
Email this Page IM this Story Bookmark this Story Add to your Del.icio.us account Digg this Story
ERIE, Pa. - An Erie cancer researcher has found a way to burn salt water, a novel invention that is being touted by one chemist as the "most remarkable" water science discovery in a century.
John Kanzius happened upon the discovery accidentally when he tried to desalinate seawater with a radio-frequency generator he developed to treat cancer. He discovered that as long as the salt water was exposed to the radio frequencies, it would burn.
The discovery has scientists excited by the prospect of using salt water, the most abundant resource on earth, as a fuel.
Rustum Roy, a Penn State University chemist, has held demonstrations at his State College lab to confirm his own observations.
The radio frequencies act to weaken the bonds between the elements that make up salt water, releasing the hydrogen, Roy said. Once ignited, the hydrogen will burn as long as it is exposed to the frequencies, he said.
The discovery is "the most remarkable in water science in 100 years," Roy said.
"This is the most abundant element in the world. It is everywhere," Roy said. "Seeing it burn gives me the chills."
Roy will meet this week with officials from the Department of Energy and the Department of Defense to try to obtain research funding.
The scientists want to find out whether the energy output from the burning hydrogen — which reached a heat of more than 3,000 degrees Fahrenheit — would be enough to power a car or other heavy machinery.
"We will get our ideas together and check this out and see where it leads," Roy said. "The potential is huge."
___
Information from: Pittsburgh Post-Gazette



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2007-09-11 12:27:49 · 7 answers · asked by Anonymous

what happens when a gas reaches it's boiling point?

2007-09-11 12:18:57 · 4 answers · asked by lalalala 1

asap.

2007-09-11 11:42:15 · 5 answers · asked by dani-elle 1

What do you call a carbon ion and a silicon ion?

Carbonide, carbide, siliconide or silicide? i cant find it anywhere

2007-09-11 11:07:48 · 2 answers · asked by people suck 6