Chemistry - March 2007

and why does it ease the movement of machines?????

2007-03-20 10:27:05 · 6 answers · asked by lauren_ziggy 1

i got no normal scale or electroic 1 i need help urgently plzz plz plz i.e. use amount of spoons or is there another method plz help some 1? and explain plz

2007-03-20 10:07:54 · 3 answers · asked by A 2

i kno what is it, but i do not know how to write it can someone give my an example please....i need an example with 8 electrons or more

2007-03-20 10:03:32 · 4 answers · asked by Anonymous

Acetic acid (HC2H3O2) has a pKa = 4.745. Determine the acetate concentration, (C2H3O2-), of a solution prepared by diluting 20.0 mL of a 0.500 M acetic acid solution with 2.39 x 10^2 mL of 1.90 x 10^-1 M HCl(aq). HCl is a strong acid. (assume volumes are additive)

I'm having a lot of trouble with this chemistry problem. Any help would be appreciated. Thank you...

2007-03-20 10:02:37 · 1 answers · asked by Anonymous

2007-03-20 09:33:38 · 15 answers · asked by babe 1

When verifying your results after balancing an equation with polyatomic ions, you should count each atom to be sure you balanced correctly.

2007-03-20 09:20:40 · 2 answers · asked by Anonymous

When balancing equations that include polyatomic ions, you can balance the polyatomic ion as a group instead of individual atoms.

2007-03-20 09:19:38 · 3 answers · asked by Anonymous

what is petroleum jelly made of?

2007-03-20 09:02:24 · 6 answers · asked by Anonymous

When separating 2 soluble solids by fractional crystallization, can they have the same solubility? Or do they have to be a little different?

2007-03-20 08:58:21 · 1 answers · asked by maretahamre 3

If 500.0ml of 0.100M HCl is added to 300.0ml of 0.200M solution of ammonia, what will be the pH of the resulting buffer?

It would be great if you could go through it step by step

2007-03-20 08:56:56 · 1 answers · asked by strawberriitwist 2

What masses of acetic acid and of sodium acetate will be needed to prepare 5.00L of an acetate buffer with a pH of 3.75 and a total acetic acid-acetate concentration of 0.150 M?

It would be great if you could go through this step by step. Thanks!

2007-03-20 08:53:30 · 2 answers · asked by strawberriitwist 2

Which of the following solutions result in a buffer ?



a) 0.050 L of 0.250 M CH3COOH + 0.100 L of 0.250 M NaOH


b) 0.100 L of 0.250 M CH3COOH + 0.050 L of 0.250 M HCl


c) 0.050 L of 0.250 M CH3COONa + 0.100 L of 0.250 M HCl


d) 0.100 L of 0.250 M CH3COONa + 0.050 L of 0.250 M HCl

2007-03-20 08:50:39 · 1 answers · asked by woj87marta 1

2007-03-20 08:33:07 · 4 answers · asked by Anonymous

why does zinc plate react quicker in a test tube then in a conicle flask and zinc powder react slower in a test tube and faster in a conicle flask. Please answer in simple terms I am thick.

2007-03-20 08:29:15 · 2 answers · asked by Anonymous

2007-03-20 07:15:03 · 1 answers · asked by Rachel F 1

A material that stays solid at room temperature, and remains solid under constant pressure, but changes to a liquid (melts) when struck. Does such a material exist?

2007-03-20 07:05:24 · 2 answers · asked by benicetodan 2

2007-03-20 06:41:24 · 2 answers · asked by orange_crush_05 6

In science I am working on a chapter in emulsions.

2007-03-20 06:32:03 · 3 answers · asked by Rebecca 1

I need to know how HCl gas can be decomposed into its elements ( hydrogen and Chlorine). what suitable arrangements of gas syringes can be used? I can not find any info on this please help

2007-03-20 06:31:02 · 3 answers · asked by Anonymous

2007-03-20 06:26:37 · 6 answers · asked by Commi N 1

i did this experiment at school and i need to know how to change these solutions below into a molar. can anyone tell me how to do this or just convert the ones underneath.
thankyou

0.9 parts water. 0.1 part sugar
0.8 parts water. 0.2 parts sugar
0.7 parts water. 0.3 parts sugar
0.6 parts water. 0.4 parts sugar
0.5 parts water. 0.5 parts sugar

2007-03-20 06:20:36 · 2 answers · asked by Anonymous

2007-03-20 06:05:13 · 23 answers · asked by Anonymous

2007-03-20 06:03:58 · 6 answers · asked by Anonymous

2007-03-20 06:03:22 · 7 answers · asked by Anonymous

2007-03-20 06:02:18 · 7 answers · asked by Anonymous

2007-03-20 05:59:03 · 8 answers · asked by Anonymous

You see people with liquid oxygen tanks and in that tank it is supposed to have like 800 times more oxygen than just a tank of oxygen. My freind works on the fire department and he said their air tanks are only good for 20 minutes (and they have the big tanks) because they are just filled with oxygen. How do you make oxygen into liquid and then turn it back to regular oxygen when it comes out of the tank to breath it?

2007-03-20 05:40:11 · 10 answers · asked by Sandi B 2

2007-03-20 05:29:57 · 1 answers · asked by Anonymous

Years ago for a science class experiment we filled balloons with the gas from Alka Seltzer tablets mixed with some liquid, and then let the balloons float away. I'm pretty sure we mixed them with water in that experiment. I know that creates carbon dioxide, but will a balloon filled with Co2 float, or did we use something other than water, and create something other than Co2?

I guess a better way to state the question would be; Alka Seltzer mixed with what liquid will create a gas that is lighter than air and would make a balloon float?

2007-03-20 05:20:09 · 8 answers · asked by Jim C 5

2007-03-20 05:11:55 · 5 answers · asked by Anonymous