Chemistry - November 2006

Explain the cooling effect experienced when ethanol is rubbed on your skin, given that

C2H5OH (l) ----> C2H5OH (g) dH = 42.4 kJ/mol

2006-11-01 13:49:39 · 4 answers · asked by Anonymous

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

2006-11-01 13:47:18 · 1 answers · asked by chris m 1

Iron (III) iodide
Na3PO4
Potassium chromate
Co(MnO4)3

I need help please.

2006-11-01 13:44:11 · 4 answers · asked by Anonymous

I've been looking everywhere and haven't a clue of what it could be.
A source would be appreciated, thanks.

2006-11-01 13:37:50 · 2 answers · asked by spks3707 2

2006-11-01 13:34:38 · 1 answers · asked by Anonymous

Like what governing body has a final say on the names of the elements.?

2006-11-01 13:33:20 · 3 answers · asked by Jessica 3

Science project.

So, I know how much salt it takes to raise water's boiling point by a degree (Celsius). However, I'm curious to know how much grams of sugar will be needed to raise water's boiling point. I know they are going to be different amounts but i'm not very clear why? Also, how many grams of sugar needed per degree?

2006-11-01 13:26:53 · 4 answers · asked by Anonymous

Estimate DH for the reaction: C2H6(g) + Cl2(g) ---> C2H5Cl(g) + HCl(g) given the following average bond energies in kJ/mol C-C, 348; C-H, 414; Cl-Cl, 242; C-Cl, 327; H-Cl, 431

a. ) -113 kJ/mol
b. ) -68 kJ/mol
c. ) -102 kJ/mol
d. ) -344 kJ/mol
e. ) 276 kJ/mol

2006-11-01 13:18:01 · 1 answers · asked by Anonymous

Which one of the following molecules has a dipole moment?

a. ) PbCl4
b. ) CS2
c. ) PF5
d. ) F2O
e. ) BF3

2006-11-01 13:16:54 · 1 answers · asked by Anonymous

Hoiw do you balance the following equation?

NaCl+H20So4=NaSo4+HCl

2006-11-01 12:55:00 · 6 answers · asked by omar v 1

I did an experiment in lab where we were determining the heat of neutralization for some solutions and we had to wash the thermometer and dry it after we measured the temp of the NaOH soln and before we measured the temp of the HCl soln...I was just wondering why we were instructed to do that....what would have happened if we didn't?

just curious....thanks!!!

2006-11-01 12:49:53 · 5 answers · asked by Anonymous

2006-11-01 12:43:02 · 2 answers · asked by Anonymous

2006-11-01 12:38:05 · 5 answers · asked by Jess 1

2006-11-01 12:33:31 · 1 answers · asked by - ѕoичтα. ☮ 4

does anyone know the name of the gas that is produced when you mix vinegar and bakign soda

2006-11-01 12:28:02 · 5 answers · asked by Bensius 2

2006-11-01 12:25:09 · 2 answers · asked by Anonymous

cant figure this answer out, please help. thank you,.

2006-11-01 12:21:42 · 4 answers · asked by Anonymous

2006-11-01 12:00:37 · 2 answers · asked by Anonymous

2 reactions:
a) H2O (s)-->H2O(l) delta H(enthalpy)=6.0 kJ, delta S (entropy)=22.1 J/K*mol
b) CaCO3(s)-->CaO(s)+CO2(g) delta H= 178kJ

which of the following is correct?
I. the reactions are spontaneous and exothermic.
II. both reactions occur with an increase in the system's disorder
III. the entropy change (deltaS*) for equation a is most likely positive.

its either I only, I and II only, II and III only, none, or all of the statements.

im confused. Because i cant tell when a reaction is spontaneous? i know that the entropy for a is 22.1 J/K (it wasnt given in the question, i figured it out to be that).
any help please??!
thanks!!!!

2006-11-01 11:54:21 · 2 answers · asked by Anonymous

I am supposed to use something strong enough to soften maccaroni shells, nuts etc., and even somewhat dissolve them if they are left in long enough. Any ideas of an easy to get liquid which is a little more acidic than basic 5% vinegar? Thanks!!!

2006-11-01 11:53:19 · 1 answers · asked by steelyourself 3

What are the formulas for the following compounds:
potassium iodide
magnesium hydroxide
aluminum sulfate
chlorine heptoxide

If you give me the answers I should be able to figure out how you got them but if you would like to take the time to explain how you reached those conclusions it would be really helpful. Thanks

2006-11-01 11:48:18 · 4 answers · asked by Anonymous

2006-11-01 11:42:52 · 2 answers · asked by twinkle 1

All of the answers are elements on the periodic table.
1.Lone Ranger's Horse.
2.Motto for an oil well-drilling company.
3.A ridiculous prisoner.
4.What do you do before you brand a steer.
5.A popular red or pink flower found in pots.
6.The kitchen on a Roman ship.
7.A roll shaped like an automobile.
8.A person from Troy who only goes out after dark. (nitrogen?)
9.What s fatally wounded person says.
10.Boards that have nailed down to walk upon.
11.The ruler of Davy Jones' Locker.
12.What kings, queens, princes, and princesses do.
13.A name for a person who talks too much.
14.Upper class of Troy.

theres a word bank so the ones i have left are:

bismuth
boron
bromine
carbon
curim
gadolinium
gallium
hydrogen
iodine
neptunium
nitrogen
phosphorus
scandium
selenium
silver

2006-11-01 11:39:04 · 3 answers · asked by BRE 2

2006-11-01 11:38:24 · 1 answers · asked by pixela007 2

4(NH3) + 5(O2 )-----> 4NO + 6(H2O)
2NO + O2 -------> 2NO2
3(NO2) + H2O -----> 2(HNO3) + NO

how can i identify the oxidizing and reducing agent in each redox reaction?

2006-11-01 11:36:57 · 1 answers · asked by pixela007 2

2006-11-01 11:28:12 · 1 answers · asked by la peruana 1

1- What's the maximum number of electrons that can occupy the third principal energy level?


2- Why do electrons fill the 4s orbital before they start to occupy the 3d orbital?

2006-11-01 11:19:28 · 2 answers · asked by Theo Z 2

Please Help Me.

2006-11-01 11:17:20 · 4 answers · asked by screameagle369 1

2006-11-01 11:04:27 · 5 answers · asked by george m 1

does a substance get hotter when it melts

2006-11-01 11:03:24 · 6 answers · asked by Anonymous