Chemistry - April 2007

2007-04-26 08:54:26 · 3 answers · asked by cassadysm 1

One of the first steps in the manufacture of garden lime,Ca (OH)2, involves heating limestone, CaCO3, to produce lime, CaO. In the process, carbon dioxide is driven off, which term below best describes this type of reaction?

A.composition
B.Ionic
C. decomposition
D. displacement
E. conservation of matter

2007-04-26 08:37:48 · 6 answers · asked by ladona c 1

My question is: Why is tungsten's symbol W instead of somethng with a T in it? Thanks for helping me!
Will award best answer!

2007-04-26 08:21:57 · 8 answers · asked by laurenelizabeth_x0 2

2007-04-26 07:26:59 · 4 answers · asked by steven k 1

2007-04-26 07:26:20 · 2 answers · asked by mrchrister93023 1

2007-04-26 07:10:46 · 6 answers · asked by ? 2

I know that bases (bitter) are tasted on the back portion of the tongue, and acids (sour) are tasted on the frontal side portions of the tongue, but are there any exceptions to this? are there some acids tasted in the bitter portions, or vice versa?
Here is the list of acids, bases, and neutrals I'm working with:

acids
Hydrogen Peroxide
Isopropyl Alcohol
Aspirin
Tonic Water
Vinegar

bases
Pepto-Bismol
Alka-Seltzer

neutral
water
saline solution

I'd appreciate your help!
Thanks in advance.

2007-04-26 07:01:33 · 1 answers · asked by Nanda 2

Ques: the ability of a substabce to assume two or more crystalline structure is called
a)isomerism
b)polymorphism
c)isomorphism
d)amorphism

Ques:in acid medium Cr2O7 changes to Cr.if pH is increased by 2 unit then the reduction potential of the half cell
a)increased by 0.28V
b)decreased by 0.28V
c)increased by 0.14V
d)decreased by 0.14V

Ques:litharge is not commonly used in
a)the manufacture of speacial glasses
b)Glazing pottery
c)Preparing paints
d)Lead storage batteries

Ques:Rbo2 is referred to as a/an
a)Oxide
b)Peroxide
c)Superoxide
d)Ozonide

Ques:COmplete hydrolysis of one mol of peroxodisulphuric acid produces
a)two mol of sulphuric acid and one mol hydrogen peroxide
b)two mol of peroxo monosulphuric acid
c)one mol each of sulphuric acid and hydrogen peroxide
d)one mol each of sulphuric acid, peroxomonosulphuric acid and hydrogen peroxide

Ques:the decomposition of H2O2 can be showed down by the addition of small amount of phosphoric acid which acts as
a)stoppper
b)detainer
c)inhibitor
d)promoter

Ques:silver is extracted from Ag2S by
a)fusing it with Kcl2 and electrolysing the melt
b)reducing it with zinc
c)treating it with sodium cyanide followed by zinc
d)roasting it and reducing the resultant product by smelting

Ques:which ire contains both iron and copper
a)cuprite
b)chalcocite
c)chalcopyrite
d)malachite

Ques:which of the following is not needed for the metallurgy of aluminium
a)carbon for electrodes
b)a flux such as cryolite
c)sodium carbonate for refining bauxite
d)Fe powder for reduction of Al2O3

Ques:sodium burns n air to give
a)Na2O
b)Na2O2
c)NaO2
d)Na2N

2007-04-26 06:52:49 · 1 answers · asked by kawal 2

2007-04-26 06:47:07 · 1 answers · asked by pcdaalvin 1

Is it posible to use photovoltaic cells to generate enough power to extract hydrogen? how much power is used in terms of wattage does it take and how do you capture and store the element after you have got it to bubble out???

2007-04-26 06:44:29 · 4 answers · asked by Anonymous

http://www.dbooth.net/mhs/chem/solubilityrules.html

2007-04-26 06:30:46 · 1 answers · asked by Jah 1

2007-04-26 06:29:07 · 1 answers · asked by Erica D 1

Can anyone help me to determine if 3-methyl-2-pentanol is or isNOT a cis/trans isomer? if you know, can you please give your reasoning. Thank you much!!

2007-04-26 06:28:21 · 2 answers · asked by ♥ Snookie ♥ 3

For 1.9 mole of the radioactive isotope phosphorus-32, half-life = 14.3 days, how many disintegrations have occurred after 17 minutes?

Please give a little explanation.

2007-04-26 05:59:26 · 1 answers · asked by dandevita 1

Strain refers to the amount of distortion a substance is subjected to by stress.


A. true B. false

2007-04-26 05:50:22 · 2 answers · asked by Anonymous

Okay. I need help with this really simple problem that I keep getting wrong.

If you measure out 49.95 mL of 0.113 molar HCl solution, how many moles of HCl would be contained in that volume of HCl? (The units for your answer is moles, but just enter the number. Use exponential form, thus 4,900 is 4.90e03)

The answer has to have correct significant figures.

My answer was 6.00e-03, but it says that its wrong. How should I do this problem to get the right answer?

2007-04-26 05:49:00 · 2 answers · asked by Anonymous

2007-04-26 05:45:56 · 2 answers · asked by Anonymous

Another wood sample prepared from an object recovered at an archaeological excavation gives a decay rate of 0.175 disintegration per second per gram of the sample. What is the age of the object?

2007-04-26 05:37:32 · 3 answers · asked by mitch v 1

2007-04-26 05:30:37 · 1 answers · asked by mitch v 1

2007-04-26 05:24:08 · 1 answers · asked by mitch v 1

Which statements are true about the reaction shown below?

CrO2- + ClO- →CrO42- + Cl-


A. Cr is an oxidizing agent.
B. Cl is oxidized.
C. O is oxidized.
D. Cl is an oxidizing agent.
E. Cr is oxidized.

more than one answer possible

2007-04-26 05:23:19 · 4 answers · asked by MEB 2

How many electrons are transferred in the redox reaction shown below?

3Cd + 8H+ + 2NO3- → 3Cd2+ + 2NO + 4H2O

2007-04-26 05:04:47 · 1 answers · asked by MEB 2

For 1.8 mole of the radioactive isotope xenon-133, half-life = 5.3 days, how many disintegrations have occurred after 20 minutes?

2007-04-26 04:33:18 · 1 answers · asked by purple222 2

Given that E°=0.52V for the reduction Cu+(aq) + e- ---> Cu(s), calculate E° for the following reaction at 25°C.

2Cu+(aq) --->Cu2+(aq) + Cu(s)

If anyone can show me how to do this problem, I would greatly appreciate it. It's not a homework problem or anything that is to be turned in, it's just something I cannot remember how to do. Thanks.

2007-04-26 04:05:06 · 1 answers · asked by Anonymous

2007-04-26 03:59:50 · 4 answers · asked by Anonymous

What is the half-life in minutes of a radioactive nuclide if 1 ⁄ 64th of the original sample remains after 116.0 min ?

2007-04-26 03:49:27 · 3 answers · asked by giggles9783 1

the density of sodium chloride solutions should have produced a straight line when plotted. How could this plot be used to determine the density of any concentration of sodium chloride solution?

2007-04-26 03:39:22 · 2 answers · asked by ADRIANN 1

Reaction N2 + 3H2<=>2NH3.

If a system of volume 0.3373 mL is prepared from 1.23526 mol of NH3, and at equilibrium there is 0.04171 mol of H2, what would the equilibrium constant be?


I have tried these evil things several times and i never understand the ugly equation. Can someone nicely structure the solution? That way i can also see how you got the answer and then i can do the other sample questions...thanks

2007-04-26 03:25:43 · 4 answers · asked by linzeeloulou 1

Anybody know of a website that would provide an MSDS for cheesecloth? Or can someone just tell me??

2007-04-26 02:07:00 · 2 answers · asked by stclairj97 1

Do the amino groups have any relation with the amino acids present in the protein molecules?

2007-04-26 00:26:09 · 5 answers · asked by Anonymous