Chemistry - April 2007

Make a list of 5 acids, bases and/or buffers you find listed on the labels of products found in your home. Share this list of 5 compounds on the discussion board, along with the product name where you found them. Propose reasons as best as you can as to why those acids or bases or buffers are in those products. (You do NOT need to list 5 acids, 5 bases and 5 buffers, just a total of 5 compounds)

2007-04-13 15:31:24 · 2 answers · asked by moonbaby29_us 1

I am currently using a neon generator: 7500V @30ma. The voltage lead to ground is separated by 1/4" of glass with approximately a 22" perimeter (8"x8"x1/4" glass with room for the stand). Around the perimeter, the electrons have approximately 2" total to travel from lead to gnd. It works very well, but I was wondering if there is a way to calculate the ideal distance to make the arcing create the most amount of ozone. Or better yet, the most efficient way to create the ozone. Any Ideas? It really does help keep my hockey equipment inside of the house by ridding it of that horrid smell.

PS, I may repost this later in the electrical section to see if anyone there has some nice ideas.

2007-04-13 15:11:37 · 2 answers · asked by Anonymous

Hi, I am having a bit of trouble with my Chemistry homework. I understand the basics of buffers, but this question is a mite complicated and I'm not quite sure how to approach it:

A buffer consists of 0.25 M NaH2PO4 and 0.15 M Na2HPO4. Phosphoric acid is triprotic with Ka1 = 7.5 × 10^-3, Ka2 = 6.3 × 10^-8, and Ka3 = 4.8 × 10^-13.
A. Which Ka value is most important to this buffer system?
B. What is the pH of the buffer?

For the first one, I'm inclined to say that Ka1 is the most important, but that is just a guess, and I don't know why any one of them would be more important than the others. Please help!

2007-04-13 14:11:29 · 2 answers · asked by eyanyo13 3

A certain mine produces 2.0 108 kg of copper from chalcopyrite (CuFeS2) each year. The ore contains only 0.90% Cu by mass.
(a) If the density of the ore is 2.6 g/cm3, calculate the volume of ore removed each year.

(b) Calculate the mass of SO2 produced by roasting (assume chalcopyrite to be the only source of sulfur).

2007-04-13 13:50:01 · 1 answers · asked by Rachel B 1

2007-04-13 13:40:50 · 2 answers · asked by ano0osh 1

A current of 250. A flows for 24.0 hours at an anode where the reaction occurring is
Mn2+(aq) + 2H2O(l) → MnO2(s) + 4H+(aq) + 2e-
What mass of MnO2 is deposited at this anode?
19.5 kg
12.9 kg
4.87 kg
2.43 kg
none of the above

2007-04-13 13:07:11 · 1 answers · asked by jennifer 2

The value of the equilibrium constant for the reaction of nickel(II) ions with cadmium metal is 1.17 × 105. Calculate ΔG° for the reaction at 25°C.
-12.6 kJ
-28.9 kJ
12.6 kJ
28.9 kJ
none of the above

2007-04-13 13:04:01 · 1 answers · asked by phong pham 2

Using the Bohr theory, derive a general equation for the frequencies of the lines of the spectrum of atomic hydrogen. Identify the expression for the Rydberg constant in your equation.

2007-04-13 12:58:06 · 1 answers · asked by Anonymous

Which of the following solids is commonly used as an inactive electrode in electrochemical cells?
zinc
graphite
copper
iron
sodium



Question 6 1 points Save
What mass of silver will be formed when 15.0 A are passed through molten AgCl for 25.0 minutes?
0.419 g
6.29 g
12.6 g
25.2 g
33.4 g


thanks in advance

2007-04-13 11:38:21 · 1 answers · asked by jennifer 2

OK bare with me because I’m no physicist or an expert in molecular structure but I'm sure I have read that when we think we touch something, say with our hands, we are not actually touching the object but feeling the repulsive charge of the electrons circling every single atom in both our hands and the object....is this correct??

2007-04-13 11:17:13 · 2 answers · asked by Anonymous

PbBr2 precipitates out. Calculate the percent yield (%) if 11.061g of PbBr2 precipitates when 1.700L of 0.0500M Pb(NO3)2 (aq) and 1.260L of 0.0562M LiBr are mixed.

2007-04-13 11:16:07 · 1 answers · asked by Anonymous

Taking CH3COOH

Is it
A) an acid
B) a base
C) both

2007-04-13 10:49:41 · 9 answers · asked by Anonymous

2007-04-13 09:33:31 · 2 answers · asked by mimi 1

Would Decreasing the volume of the system cause the equilibrium to shift to the left? Would decreasing the pressure? Would decreasing the temperature? Would adding SO2 to the system shift the equilibrium to the left? What about removing SO3?

2007-04-13 09:21:50 · 3 answers · asked by theweirdguy1 2

polydentate ligands result in more stable complex ions
then do monodentate ligands



An example of formation equilibrium for a complex ion in solution is:

Al3+ + 6F− ↔ [AlF6]3− Kf = 5.0 × 10−3



ΔG = −RT ln( Kf )



remember, the more negative the value the of ΔG the more stable
are the products of reaction that are formed




Which of the following are true statements ?



a) en stands for ethylenediamine, a bidentate ligand


b) The subscript f in Kf stands for 'free energy'


c) A very small value of Kf for a chemical reaction in which a coordination complex
is a product would indicate that the complex formed is a relatively stable one


d) A very large value of Kf for a chemical reaction in which a coordination complex
is a product would indicate a relatively small decrease in Gibbs free energy

2007-04-13 09:06:12 · 2 answers · asked by Anonymous

A chemist claims to have found a complex ion where the most intensely absorbed light is 491.0 nm. Estimate the crystal field splitting energy for this ion in kJ/mol.

2007-04-13 09:05:34 · 1 answers · asked by Anonymous

2007-04-13 09:00:05 · 1 answers · asked by Anonymous

How many unpaired electrons does this cation have? Why?

2007-04-13 08:58:51 · 1 answers · asked by Anonymous

Explain (provide structures and orbital diagrams).

2007-04-13 08:55:49 · 1 answers · asked by Anonymous

2007-04-13 07:56:59 · 5 answers · asked by gramsue 1

Can anyone help me out with this: In a coffe-cup clorimeter, 125 mL of a 2.75 M solution of silver nitrate at 25.00 degrees C is comined with 350 mL of a 4.00 M strontium chloride solution, aslo at 25.00 C. The temperature of the final solution is 32.15 degrees C. If the density of the final solution is 1.25 g/mL and the heat cpacity of the final solution is 4.33 J/C*g, calculate delta H of silver chloride formed.

Any help would be highly apreciated, even if its just giving me a push in the right direction.

2007-04-13 07:39:17 · 1 answers · asked by Anonymous

the cause of toxicity

2007-04-13 07:28:42 · 2 answers · asked by just me 1

2007-04-13 07:18:58 · 1 answers · asked by Anonymous

For the reaction


CH4 + O2 → CO2 + H2O


80.20 g of CH4 are completely reacted with an excess of the other reactant.


If the percent yield is found to be 88.82 %, how many grams of H2O are actually produced ?

2007-04-13 07:13:46 · 1 answers · asked by John S 1

? supposedly broccoli is a source of calcium.

2007-04-13 06:19:06 · 1 answers · asked by Anonymous

How can i measure the reaction rate between HCl and NaOH?
Its just an acid base reaction, i dont see what product could be measured as such

And help/ideas would be much appreciate

2007-04-13 06:11:25 · 7 answers · asked by Anonymous

lead to the transfer of C)2 from the atmosphere to the geosphere?

2007-04-13 06:05:13 · 1 answers · asked by jumpy789 1

...and how is that done?

2007-04-13 05:42:10 · 9 answers · asked by Aubie 4

95.80 g of LiOH are completely reacted with an excess of the other reactant.

If the percent yield is found to be 92.88 %, how many grams of H2O are actually produced?

2007-04-13 05:23:12 · 2 answers · asked by Anonymous

2007-04-13 05:18:13 · 2 answers · asked by bmoon12345 1