Chemistry - March 2007

2007-03-21 15:53:43 · 8 answers · asked by kfff s 1

what is the relationship between proton electron and neutron??

not only the mass or the location
but everything please!!

2007-03-21 15:50:32 · 8 answers · asked by yu ca 4

Explain the:
- action of white light.
- range of colours
-range of threshold
-what happens when you change the intensity
-what happens to kinetic enegry

2007-03-21 15:46:38 · 1 answers · asked by Chantal D 1

107.0 mL of a solution of quinine contains 224.7 x 10-3 mol of quinine.
If this is titrated with 0.200 M HCl, what is the pH half-way to the stoichiometric point ?

Quinine is monobasic with Kb = 7.90 x 10-6

2007-03-21 15:40:48 · 1 answers · asked by Anonymous

What electron structure do noble gases have in common?

2007-03-21 15:37:01 · 5 answers · asked by USEyourBRAIN 2

What is the process?

2007-03-21 15:36:43 · 2 answers · asked by torirowe 2

what a harsh day in chemistry class..
omg there is a test comin soon
can anyone help me define /expain and observed behavior of gases.

Boyle's law
charles' law
combined gas law
dalton's law of partial pressures
diffusion
effusion
gay-lussac law
ideal gas constant
ideal gas law
partial pressure

i'm will be glad if you can help me on my test...

2007-03-21 15:33:31 · 4 answers · asked by alan l 1

Calculate the pH of the solution that results from the addition of 0.020 moles of HNO3 to a buffer made by combining
0.500 L of 0.140 M HC3H5O2 ( Ka = 1.30 x 10-5 )
and 0.500 L of 0.140 M NaC3H5O2

2007-03-21 15:28:06 · 5 answers · asked by Anonymous

calculate the volume of products formed when 5 grams of C3H8O reacts in excess O2. Then calculate the pressure exerted by the gaseous products if the reaction occurs in a 3.78L container at 25 dergree in celsius.

2007-03-21 15:27:46 · 2 answers · asked by Anonymous

Does adding salt to water increase the number of ions? how and why?

2007-03-21 15:27:45 · 2 answers · asked by Anonymous

http://www.angelfire.com/scifi/ricks/genius-reactions.html

Can somebody explain to me the solubility constant is and how to use it? Thanks

2007-03-21 15:25:46 · 3 answers · asked by Selena S 2

i don't understand what i put after the yeild sign in this equation.

Al(s) + Fe2O3(s)

info: Elemental irn is produced in what is called a thermite reaction because it produces enough heat that the iron is intially in the molten state. the liqiud iron can then be used to weld bars together.

question: What mass of Al is needed to produce 750g of Fe? How many formula units of FeO3 are used in this process( i don't get this second part to the question)

please help.

2007-03-21 15:20:53 · 2 answers · asked by Stephanie 3

I have had to learn a LOT of equations in just a few CHAPTERS in my Gen. Chem II class in college. I'm DREADING the final. How on EARTH do you remember all this stuff from memory?

2007-03-21 15:19:09 · 2 answers · asked by I_color_outside_the_lines 4

i want to do a science fair project about hard water but i dont know what kind of test to do with it.

2007-03-21 15:16:59 · 6 answers · asked by Stishott 3

2007-03-21 15:15:30 · 4 answers · asked by Anonymous

Can someone please explain to me how to find the pH of a buffer solution? I don't understand at all.

If you can walk me through this example, that'd help a lot.

Calculate the pH of a buffer that is 0.0858 M in NaHCO3 and 0.120 M in Na2CO3.

I think this is the right Ka value:
Ka for H2CO3
Ka1 =4.3E-7 Ka2 =5.6E-11


Thank you so much in advance...I really need to understand this..

2007-03-21 15:06:37 · 2 answers · asked by protege moi 3

This is not a homework question- I just am trying to figure it out in my head.

2007-03-21 14:55:52 · 1 answers · asked by Anonymous

2007-03-21 14:50:58 · 2 answers · asked by cubiche00 1

Is Pb(NO3)2 insoluble or is AgNO3 insoluble?
OR are they both soluble or both insoluble?

2007-03-21 14:49:52 · 1 answers · asked by Jessica 1

2007-03-21 14:40:27 · 6 answers · asked by sami771991 1

I just do not get it, will someone help me please?

Use the Rydberg equation to calculate the wavelength (in Å) of the photon absorbed when a hydrogen atom undergoes a transition from n = 1 to n = 2.

2007-03-21 14:32:24 · 2 answers · asked by pinay804 2

a friend of mine's daughter died and in the toxicology reports indicate in the girl's body enough cocaine to kill a grown man, GHB in the system and 'possible' chloroform. So I was wondering if mixing these two drugs might produce traces of chloroform in the system.

2007-03-21 14:29:13 · 2 answers · asked by midnightdealer 5

These r the electron configs:
A) 1s2 2s2 2p6 3s1
B) 1s2 2s2 2p3
C) 1s2 2s2 2p6 3s2 3p2
D) 1s2 2s2 2p4
E) 1s2 2s2 2p6 3s2 3p6 4s1
F) 1s2 2s2 2p6 3s2 3p6 3d2 4s2
PLEASE HELP ME!!!

2007-03-21 13:54:30 · 1 answers · asked by truckin_90 2

A aton of a element has 2 electrons in the 1st energy level & 5 electrons in the 2nd enegry level. Write the elctron configuration for this atom & name the element. How many unpaired electrons does a atom of this element have?

2007-03-21 13:47:52 · 2 answers · asked by truckin_90 2

chem question

please explain.

2007-03-21 13:41:33 · 7 answers · asked by ASDF 3

HCL
CaO
NH3
O2

2007-03-21 13:16:07 · 3 answers · asked by AVR 1

110.0 mL of a solution of quinine contains 231.0 x 10-3 mol of quinine. This is titrated with 0.200 M HCl.
Quinine is monobasic with Kb = 7.90 x 10-6

2007-03-21 13:14:15 · 2 answers · asked by Anonymous

Costa prepares a buffer solution that contains aqueous ammonia (NH3) and ammonium chloride (NH4CL). The reactions that make the buffer work are

NH3+H3O -------><--------- NH4 + H2O
NH4 + OH -------><--------- NH3 + H2O

What I don't get are the reactions that make the buffer work? How come there's 2 reactions that make the buffer work?
And what happened to the ammonium chloride?
Can someone help me understand what is going on?

2007-03-21 13:05:30 · 2 answers · asked by Anonymous

What is the relationship of NH4Cl to NH3?

2007-03-21 13:01:30 · 2 answers · asked by Anonymous

2007-03-21 13:00:39 · 16 answers · asked by reatho 1