Chemistry - November 2007

The air in the balloon is then heated to 60.°C, causing the balloon to expand to a volume of 4.50 103 m3. What is the ratio of the number of moles of air in the heated balloon to the original number of moles of air in the balloon? (Hint: Openings in the balloon allow air to flow in and out. Thus the pressure in the balloon is always the same as that of the atmosphere.)

i need a ratio as heated air over cool air

2007-11-17 08:22:58 · 2 answers · asked by Anonymous

(Ka1 = 7.2 10-3, Ka2 = 6.3 10-8, and Ka3 = 4.2 10-13).
(a) Which Ka value is most important to this buffer?
b) What is the buffer pH?

2007-11-17 08:21:11 · 1 answers · asked by Ecka 1

2007-11-17 08:20:42 · 9 answers · asked by rainkimmy 1

How many isomers (including all stereoisomers) exist for dibromopentadiene?

No, you do not have to draw out every single one. It is using the 2^n formul, where n=chiral centers along with subtraction for meso structures. I know you also have to factor in cis and trans possibilities with the structures as well.

I thought I'd put this in the right category, since I screwed up before.

2007-11-17 08:19:30 · 1 answers · asked by mosspoh 1

1. What is the wavelength of a 19F+ ion which is moving with a speed of 4.255x10^5 m/s?

2. In what row or period of the periodic table do we encounter a d-electron? 4, 3, 5, 6, 2
I think the correct one is period 3?

2007-11-17 08:10:27 · 1 answers · asked by S281 2

A) Calculate the pH of a buffer solution that contains 0.60 M NaH2PO4, and 0.15 M Na2HPO4.

B) What volume (L) of 0.408 M potassium hydroxide solution would just neutralize 100.6 ml of 0.380 M H2SO4 solution?

2007-11-17 07:55:16 · 1 answers · asked by Peter 2

2007-11-17 07:48:33 · 1 answers · asked by edward g 3

Doing Chemistry Need Help
Greatly Appreciated Thanks

2007-11-17 07:41:40 · 3 answers · asked by Anonymous

Is water unique in having its solid form less dense than its liquid?

2007-11-17 07:18:45 · 4 answers · asked by Ptericytol 1

2007-11-17 06:45:06 · 1 answers · asked by little bird 2

I'm using Secret. The ingredients are:
Aluminum Zirconium, Tichlorohydrx GLY
Dimethicone
Tribehenin
C18-36 Acid Triglyceride
Pentadecadecalactone

2007-11-17 06:06:37 · 1 answers · asked by beingagood1 5

I am trying to find out what this solid is. It looks like a really small rock. Two of them were stuck together and when I took them apart it looked like metal was stretching. I found the density was 3.21g/ml3. Its not magnetic, and has a melting point after 650 degrees C. I can't figure out what it is.

2007-11-17 06:03:18 · 1 answers · asked by Anonymous

C-14 has a half life of 5730 years. Charcoal with a 1/4 of the amount of C-14 as a living tree would have burned how long ago?

2007-11-17 06:00:31 · 5 answers · asked by Macgyver with Crosby 4

So last year i was told that we draw an atom with the nutrons and protons in the middle, then we put rings around and electrons would be represented as 'X', drawing 2 (North, South) on the first ring.

4 (North, South, East, West) on the second ring.

8 on the next ring (North, South, East, West, North, South, East, West), meaning we would have 2 paired up at each point, the next would have maximum of 3, ect.

This year we are told that we should draw the "X", East, West, North South, does it really matter, and is there a correct way of drawing an atom in that matter, and whats its name, as it isnt the same as a Bohr Atom.

Thank-you

2007-11-17 05:40:00 · 4 answers · asked by Paul W 1

2007-11-17 04:58:13 · 3 answers · asked by Sweetness 1

can you give me an intensive description of ketones, uses in industry and simple experiments that can be conducted with them?? i need a lot of information and i have already checked several search engines but i need more info...

2007-11-17 04:45:09 · 2 answers · asked by curiousperson 2

A photon of ultraviolet (UV) light possesses enough energy to mutate a strand of human DNA. What is the energy of a single UV photon having a wavelength of 39 nm?
5.1e-18 J

that was the first question...but then it asks:
What is the energy of a mole of UV photons having a wavelength of 39 nm?
-the answer is in Joules


please explain it!

2007-11-17 04:38:43 · 1 answers · asked by s.weiss 1

For example:
what is the difference between 2O and O2?
And how would you write something like in a word equation?

2007-11-17 04:30:29 · 1 answers · asked by ..... 1

Calculate the number of moles of nitrogen collected.
n= PV/RT
P= Patm -Ph2o - (23.5/13.6)
V=28.5 ml .0285L
R= .082
T = 22c 295.15K

I keep getting a negative number for P is this right.


formula given for P
(760 mmHg/ 1) x (1 atm/ 760 mmHg) - (Ph2o in torr/ 1) x (1 atm/ 760 mmHg) - ( height of bubble 23.5 cm h2o/ 1) x (760mmHg/ 13.6 cm h2o) x (1atm/ 760mmHg) =
Report It

2007-11-17 04:24:00 · 1 answers · asked by Anonymous

does anyone know the balanced chemical equation for the combustion of 1-pentanol please?!

2007-11-17 04:21:46 · 1 answers · asked by cksb 1

2007-11-17 04:21:18 · 3 answers · asked by Davie J 1

I cant seem to get the right answer to this:

What is the frequency of a photon with a wavelength of 3.20 10-5 m? (The speed of light in a vacuum is 2.998 108 m/s. Planck's constant is 6.626 10-34 J·s.)

2007-11-17 04:13:16 · 4 answers · asked by Guy 2

Explain why, at room temperature, carbon dioxide is a gas but carbon disulfide is a liquid.

2007-11-17 04:09:00 · 3 answers · asked by Anonymous

Like, I need to know which element they are and which food they are contained in. It's for this project i have to do in Science. We have to create a periodic table of food. Any help will be greatly appreciated!!

2007-11-17 03:58:07 · 4 answers · asked by Just~B~N~Me!! 1

not getting any references,it is in the region of adsorption on solid surface....

2007-11-17 01:29:00 · 2 answers · asked by Anonymous

I understand that caffeine is only slightly soluble in water and very soluble in dichloromethane. What I want to know is what intermolecular force attracts the caffeine to the dichloromethane and what atoms are involved in the attraction?

2007-11-17 01:14:37 · 1 answers · asked by allgae 1

When you get sodium to react with acid sulfuric solution, which will react first, water in the solution or the acid???

2007-11-17 01:14:36 · 2 answers · asked by Daniel G 2

What would the equations be with aspirin reacts with HCL and NaOH? I know the equations for Aspirin reacting with NaOH in distilled water. These are the equations I need to know:

Aspirin + 1mol HCL + 1 mol NaOH
Aspirin + 0.5mol HCL + 1mol NaOH
Aspirin + 0.25mol HCL + 1 mol NaOH

Aspirin + 1 mol HCL + 0.5mol NaOH
Aspirin + 0.5mol HC + 0.5mol NaOH
Aspirin + 0.25mol + 0.5mol NaOH

Aspirin + 1mol HCL + 0.25 mol NaOH
Aspirin + 0.5mol HCL +0.25mol NaOH
Aspirin + 0.25mol HCL + 0.25 mol NaOH

Just to check:
Aspirin + distilled water + 1 mol NaOH
Aspirin + distilled water + 0.5mol NaOH
Aspirin + distilled water + 0.25mol NaOH

Any help would be most appreciated!

2007-11-17 00:43:23 · 1 answers · asked by Anonymous

When I mix these two in solution a precipitate forms at the bottom. It is a waxy substance with a seemingly higher concentration of lavender oil than the castile soap normally has. My hypothesis is that the epsom salt is dissolving the water soluble parts of the soap into the solution and leaving behind the lipophilic and phenolic compounds in the soap.

2007-11-16 23:43:12 · 1 answers · asked by TC766H 2

2007-11-16 23:29:38 · 5 answers · asked by Mandeep S 1