Chemistry - September 2007

In any distillation for maximum efficiency of the column, the distilling flask should be approximately 1/2 full of liquid. Comment on this fact in terms of a) a flask that is too full and b) a flask that is nearly empty.

I don't know about a)...

For b), it shouldn't be nearly empty because the liquid might dry out before you can get the distilled solution? Or it won't make enough distilled solution???

2007-09-07 19:36:16 · 2 answers · asked by Anonymous

4.88 mol H2O2

2007-09-07 19:22:31 · 2 answers · asked by MB 4

2007-09-07 19:16:19 · 1 answers · asked by Giselle 1

It is an ingredient in soapmaking.

2007-09-07 19:13:29 · 4 answers · asked by Ed A 1

what is paper chromatography?

2007-09-07 19:06:36 · 1 answers · asked by Amsterdam c 1

I. You ran two chromatography tests, using the same dye
a. In the first experiment you used a strip of paper ten cm long, and the second 20 cm. Will the Rf value be the same or not?
b. In the first experiment you used water as a solvent, and the second ethyl alcohol as a solvent, will they be the same or different?

II. You ran two chromatography tests, with different dye
a. with the same size strip of paper, and solvent. Same or different?


I would appreciate help, and I would appreciate thorough answers more. Thank you very much.

2007-09-07 17:19:17 · 2 answers · asked by vince_oy 3

2007-09-07 17:16:14 · 1 answers · asked by khosyieaz 1

Suppose 1.20g of c2h2 is mixed with 3.50g of o2 in a closed, steel container, and the mixture is ignited. What substances will be foundd in the mixture left when the burning is complete? I have no clue how to approach this...

2007-09-07 16:47:40 · 2 answers · asked by kleo 4

What store would sell glass piping?

2007-09-07 16:29:21 · 2 answers · asked by Anonymous

Can you please show all working out, this is only about 20% of my question. I need the working all to be able to complete the rest.

1) What mass of solute is needed to prepare:

a) 500mL of 3.0M HCl

2) Vinegar is a solution of acetic acid (CH3COOH) in water. If 200mL of vinegar contains 8.0g of acetic acid. What is the molar concentration of acetic acid in vinegar

3) A compound has the following percentage composition by mass: 32% carbon 6.7% hydrogen 18.7% nitrogen and 42.6% oxygen

Find the empirical

8) A hydrocarbon contains 90% carbon and 10% hydrogen. Find the empirical formula.

2007-09-07 16:17:21 · 5 answers · asked by Anonymous

a. CL
b. O-
c.Br-
d.Cl+

Can someone please explain electronic configurations in laymen's terms (if possible?) I'm clueless!

2007-09-07 15:46:03 · 5 answers · asked by kleo 4

Im looking for whatever Chloride is. Like Hydrogen is (H) and Oxygen is (O), but what is chloride? I know sodium Chloride is NaCl, but what is Chloride on it's own? It's not Cl, that is calcium...what is it???

2007-09-07 14:27:23 · 12 answers · asked by tjsmartypants 1

Why not oxygen gas? I'm just curious as to why it is carbon dioxide in soda. What makes it better than any other gas for the job?

2007-09-07 13:54:49 · 6 answers · asked by Dr. Evil 2

2007-09-07 13:44:23 · 4 answers · asked by roni 1

What is the most likely mechanism for the following reaction? (Write the symbol for the reaction mechanism.)
http://i5.tinypic.com/4teyukn.jpg

2007-09-07 13:28:01 · 3 answers · asked by Anonymous

I know that you can use percentage error to compare the correct accepted value of one value with the average you got. But what formula would I use to compare a set of 6 results (3 from 2 people each) in terms of accuracy and precision?

2007-09-07 12:50:30 · 2 answers · asked by Anonymous

volume of seawater (in liters) needed to extract 2.2 X 104 tons of K. (Density of seawater is 1.03 g/mL.)

2007-09-07 11:41:45 · 2 answers · asked by lillil 2

answer with reference to structure and bonding

2007-09-07 11:31:37 · 6 answers · asked by Mona 2

the question is to find the width of a piece of 10 by 10 cm aluminum foil. the foil weighs 0.4 g. the teacher gave a hint by saying it has something to do with the density of the foil, which is given on the periodic table.

any help plz?

2007-09-07 11:30:45 · 5 answers · asked by Anonymous

A classmate of mine saw a video of a mineral oil submersed computer and im slightly skeptical about the idea, he wants to build one for a school, but i need to know if the mineral oil is conductive and if the website is pulling legs.

2007-09-07 11:06:27 · 7 answers · asked by TheBlueBeast 2

what are the mole fraction of benzene (C6H6), and toluene (C7H8),in a solution prepared by adding 500 g of benzene to 500g of toluene?
plz someone explain it!!!!

2007-09-07 10:58:14 · 2 answers · asked by Anonymous

plz someone explain it!!!!

2007-09-07 10:51:33 · 1 answers · asked by Anonymous

ok so, i have a mean prof who wants this worked out asap. if you could just give my the general walk through or hints to what i need to do, that would be awesome, i've read the chap and such still don't understand how. oh by that way this is what i am given thank you soooo much!
boiling pt of solute=89.0C,
H2O=100C,
M(unknown)=4.41g,
M(h2o)= 99.72g .
Kb(C/m)=.52(H2o)

NaCO3=105.99 g/mol
NaHCO3=84.008g/mol
NA3PO4=163.94g/mol
KHC8H4O4=116.22g/mol

2007-09-07 10:34:30 · 1 answers · asked by Anonymous

plz someone explain it!

2007-09-07 10:27:51 · 1 answers · asked by shima 1

2007-09-07 09:51:31 · 5 answers · asked by iluvwomen6964 2

plz help!!

2007-09-07 09:49:12 · 1 answers · asked by shima 1

The standard enthalpy of vaporization (DeltaH°vap) of n-pentane (CH3(CH2)3CH3) is 27.6 kJ/mol.
The normal boiling point of n-pentane is 36.1°C.
Calculate the vapour pressure of n-pentane at 13.1°C.

And please explain how to solve?

2007-09-07 09:42:52 · 1 answers · asked by Anonymous

2007-09-07 09:41:12 · 4 answers · asked by nothingspecial 1

i checked the psychoactives list in erowid and i fided there an chocolate vault! check for yourself if you don't belive me:
http://www.erowid.org/chemicals/chocolate/chocolate.shtml

2007-09-07 09:40:47 · 2 answers · asked by Anonymous

2007-09-07 09:35:23 · 8 answers · asked by mistickle17 5