Chemistry - March 2007

2007-03-11 00:14:25 · 11 answers · asked by Anonymous

2007-03-11 00:09:47 · 2 answers · asked by . 6

2007-03-11 00:08:21 · 3 answers · asked by Anonymous

2007-03-10 23:49:45 · 2 answers · asked by Jessica C 1

(please put below in order) thank you

A. Move the 10x objective into position.

B. Focus the object sharply with the fine focus.

C. Turn power switch on and switch on the microscope itself.

D. Place the slide to be looked at on the stage. Make sure the specimen appears to be illuminated by the light.

E. While looking from the side, raise the stage until it is very close to the objective lens. Then while looking through the eyepiece slowly lower the stage until the object is in sharp focus.

F. Move the 40x objective lens into position.Focus the object using the fine focus only.

G. Adjust light intensity - separation of the eyepieces to a comfortable level.

H. Move the condenser assembly to its highest position.

2007-03-10 23:21:59 · 1 answers · asked by Anonymous

i know that the amount of a catalyst would charged after an experiment ...

2007-03-10 23:16:29 · 3 answers · asked by qian 1

2007-03-10 23:03:57 · 2 answers · asked by Anonymous

In our textbook it says "By convention, current flows from the positive electrode of a cell to the negative electrode. Actually, it is the electrons that are flowing. The flow of currnet and electrons are opposite in direction." I know that electrons in the external circuit flow from the negative terminal to the positive terminal, but the sentence in our textbook seems quite confusing. Can someone please kindly explain this? Thanks!

2007-03-10 22:52:06 · 5 answers · asked by Anonymous

i need help on these 2 problems!
1. If a 2.0 grams radioactive substance has a half-life of 20 minutes, how many half-lives have occurred in 120 minutes?

2. If a 2.0 grams radioactive substance has a half-life of 20
minutes, how much remains after 120 minutes?

2007-03-10 20:43:33 · 2 answers · asked by orange_crush_05 6

How many covalent bonds are there?
How many single/double covalent bonds?

2007-03-10 20:16:42 · 2 answers · asked by cosmo08 2

Hi,
I have to give names and draw the structural formulae for all the isomers of C5H10, i'm really not sure what to do!

Thanks

2007-03-10 19:47:32 · 4 answers · asked by Anonymous

The gems (rubies and sapphires) are slightly impure forms of Al2O3(Aluminium Oxide), so why do they display different colours?

2007-03-10 19:20:20 · 2 answers · asked by Diana L 2

Question: (a) What is the pH of 0.0333 M HNO3? Is the solution neutral, acidic or basic? (b) what is the pOH of 0.0347 KOH? Is the solution neutral, acidic or basic?

My Approach:
(a) I found pOH as 1.48 and then I calculated the pH using the Kw and got 12.5. It was also a basic solution.

(b) I found pH at 1.46 and then figured out pOH at 12.5...My conclusion is that it was basic solution.

So what do you think? Am I correct? What do you i need to fix? Thanks for all the help I get!

2007-03-10 19:20:01 · 3 answers · asked by Jimmy 3

2007-03-10 19:17:07 · 1 answers · asked by vino 1

2007-03-10 19:16:34 · 4 answers · asked by aza_007 1

Question: Write the Ka expression for each of the following in water: (a) H2PO4-, (b) H3PO2, (c) HSO4-

My Approach:

(a) H2PO4 - + OH- <----> H2O + HPO4 2- >>> ka = [HPO4]/[OH-][H2PO4]

(b) H3PO2 + OH- <---> H2O + H2PO2 - >>> ka = [H2PO2]/ [OH][H3PO2]

(c) HSO4 - + H2O <----> H3O+ + SO4 2- >>> ka = [H3O][SO4]/ [HSO4]

I know I'm probably not right, but I cannot see it any other way. Can someone help me correct my problems either by explaining or showing me the right answers? Thanks!

2007-03-10 19:15:46 · 3 answers · asked by Jimmy 3

2007-03-10 18:53:10 · 3 answers · asked by ahh_900 1

2007-03-10 18:51:44 · 2 answers · asked by ahh_900 1

I am adding acetic acid to wash the copper chromite.Existing pH is 5.5.In this situation how can i increase the pH upto 6.5 to 7.0

2007-03-10 18:28:21 · 2 answers · asked by prakash1162 1

2007-03-10 18:09:00 · 7 answers · asked by Anonymous

2007-03-10 17:39:54 · 2 answers · asked by pooch 1

raw material and process used to manufacture thermocol and how are different shapes given??

2007-03-10 17:33:39 · 4 answers · asked by ramesh a 1

2007-03-10 17:08:32 · 6 answers · asked by valdez p 1

2007-03-10 17:05:39 · 8 answers · asked by BaKhoi Le 1

2007-03-10 16:39:35 · 1 answers · asked by pooch 1

2007-03-10 16:34:24 · 2 answers · asked by pooch 1

2007-03-10 16:32:14 · 2 answers · asked by wintersun_elyse 1

Any current news about solutions (homoegeneous, hetero, chemistry) in the world right now would be appreciated.

2007-03-10 16:07:13 · 3 answers · asked by Wannnnng 1

2007-03-10 15:49:31 · 5 answers · asked by sandeep k 1

can someone please help me with this question? i am trying to write a chem lab and i need some help.

AgC2H3O2 (aq) + KCNS (aq) ->???

2007-03-10 15:44:49 · 2 answers · asked by leafsfan1221 1