Chemistry - November 2007

2007-11-07 12:38:33 · 6 answers · asked by tiera w 1

Fe*3O*4(s)+H*2(g) -->3Fe(s) +H*2O(l)

2. C*6H*5OH(s) + O*3(g) --> CO*2(g) + H*2O(l)

2007-11-07 12:38:15 · 3 answers · asked by (: Muffin Man :) 2

Scientists often look at other galaxies and by studing them in the telescope they seem to know what elements that galaxy mostly has.

So my question is are all the elements in the known universe been found or are they using the current knowledge we have on elements to make this prediction?

2007-11-07 12:35:15 · 5 answers · asked by jack 6

Compared to solids and liquids, the particles of gases are very far apart. Because of the significant amount of space between particles, gases are easily compressed.

Using what you know about the compressibility of gases, explain why oxygen in a SCUBA tank is compressed.

2007-11-07 12:33:14 · 3 answers · asked by blessed 1

What is the effect, if any, on the following equilibrium system if the volume was reduced? Explain.

2IBr --> I2 + Br2

2007-11-07 12:31:20 · 2 answers · asked by Anonymous

put 3.27 micrograms of C2H3Cl3 into moles.
a) .0245 mol
b) .0675 mol
c) 2.45E-8 mol
d) 6.75E-8 mol
e) 2.45E3 mol

I worked out the problem numerous times, but still couldn't come up with an answer that was available. Can someone walk me through it!?! thanks

2007-11-07 12:20:47 · 3 answers · asked by BlanketyBlank 4

ok i just need to know if the following are a chemical change or physical changes.

1.tearing paper
2.burning paper
3.dissolving nacl
4.mixing nacl and AgNo3
5.tearing mg ribbon
6.adding Hcl to Mg
7. grinding CuSo4 and 5 H2O
8.heating CuSo4 and 5H2o
9. mixing Fe and
10. heating a mixture of Fe and S

umm if your not sure of one just put idk or something or you could just answer the ones you knoww that would be a lot of help too.

just don't put stupid stuff or wrong answers cause you might confuse me

2007-11-07 12:16:18 · 4 answers · asked by Anonymous

1) I know there are resonance structures for the N2O4 molecule. How do you find the average N-O bond order?

2)which atom is most likely to have less than an octet in its molecules:

- Sulfur?
OR
- Boron?

2007-11-07 12:12:20 · 2 answers · asked by mhicks04 1

Why do we need ether to form a grinard reagent? More specifically, why does it need to be anhydrous ether?

Reaction Example:

Ar-Br + Mg, ether = Ar-MgBr
(Ar is an aromatic ring)

2007-11-07 12:10:35 · 2 answers · asked by Chemnerd 1

2007-11-07 11:45:57 · 4 answers · asked by cara v 1

I need help finding the formulas and other symbols for these substances.
1. metallic potassium
2. sodium chloride dissolved in water
3. heat supplied to a chemical reaction
4. liquid mercury
5. zinc chloride as a catalyst
6. carbon dioxide gas

2007-11-07 11:43:39 · 1 answers · asked by (: Muffin Man :) 2

2007-11-07 11:43:34 · 1 answers · asked by Anonymous

If 5g of butter are burned in a calorimeter containing 1 L of water (density of water is 1g/mol), the temperature of the water rises from 21°C to 66°C. determine the amount of energy that is transferred to the water.

Q = mCT
=(1005g)(4.184J/g•°C)(66°C - 21°C)
=189221.4J

I think I'm wrong though... Will you help please?

2007-11-07 11:43:07 · 1 answers · asked by Anonymous

yeah this is mad hard.
so if anyone has an image could they put the url up in their browser?

:] thanks bunches

2007-11-07 11:40:20 · 1 answers · asked by Anonymous

What happens when electrons in atoms are heated or energized by electricity?
When do atoms release energy?
In what form is that energy released from the atom? Is that form always visible?

whoever can answer the most wins

yeah I know I'm asking you to do my homework but I really don't care

2007-11-07 11:31:44 · 1 answers · asked by Lucy 2

i really need this explanation cause i dont know it and its on my HW thats worth lots of points i thought i had another day to study but i guess not PLZ HELP!!!!!!!!!!!!!

2007-11-07 11:28:31 · 1 answers · asked by Anonymous

1. What distance does electromagnetic radiation travel in 50.0 mu_s?

2007-11-07 11:22:09 · 1 answers · asked by Anonymous

what mass of sodium carbonate was contained in that solution?
help, please? it would be great if you could explain it to me!!
thanks
x

2007-11-07 11:10:18 · 1 answers · asked by Sara R 2

2007-11-07 11:04:37 · 3 answers · asked by Anonymous

Okay. I have 127.2 grams of C7H5(NO2)3 or 0.5600 mol C7H5(NO2)3 or 3.37x10^23 particles of C7H5(NO2)3. I need to somehow determine the number of N atoms. How could I go about doing so? I assume I need to multiply one of the amounts by a fraction or something but I don't know the formula.

2007-11-07 11:00:12 · 1 answers · asked by Brookeachu. 2

Calculate the pH of each of the solutions and the change in pH to 0.01 pH units caused by adding 10.0 mL of 2.73-M HCl to 550. mL of each of the following solutions.

Change is defined as final minus initial, so if the pH drops upon mixing the change is negative.

a) water

pH before mixing=7
pH after mixing= ?

The pH after adding an acid I know is going to be <7. I am just having trouble calculating it.

2007-11-07 10:39:15 · 1 answers · asked by Anonymous

my chem teacher told me that because battery acid is an acid and drano is a base that if you mix them it is drinkable

2007-11-07 10:36:11 · 4 answers · asked by jrobuck13 2

Is detergent similar to oil.. if it's not like oil
when ur hands r rusty.. -n- u go wash the dishes... when ur done why r they not rusty.

2007-11-07 10:05:27 · 8 answers · asked by Mee-Mee G 1

2007-11-07 09:34:06 · 2 answers · asked by nyyfan 1

It's got 6 letters. The fourth one is an I.
I've narrowed it down to these:

Barium
Cerium
Cesium
Curium
Erbium
Osmium
Indium
Radium

It's a metal and is rare, but is found in some photoelectric cells and in atomic clocks.

2007-11-07 09:22:14 · 4 answers · asked by michelle8 4

If you are given 626mmhg for pressure, to solve for volume, in the above formula,do you have to change this into atm pressure, or can you use either in the P part of the equation? Which would be 626mmhg/760mmhg for the conversion to atmoshere pressure. If I knew this, the gas laws would be a little easier. Thanks for help, I like chemistry, but it can get a little hairy!

2007-11-07 09:09:41 · 4 answers · asked by dannchris@sbcglobal.net 1

2007-11-07 09:03:15 · 6 answers · asked by Anonymous

what are the major raw materials in bobby pins?

2007-11-07 08:56:25 · 1 answers · asked by Anonymous

A) .3 m
B) .2 M
C) .2 m
D) .2 g

2007-11-07 08:54:47 · 1 answers · asked by wtimm99 1

This is kind of a lame question, but I'm not exactly sure how in depth the answer has to be:
When you check your car windshield tonight (or tomorrow morning) explain why it will be wet. Base your answer upon chemical principles.
Thanks in advance for any help!

2007-11-07 08:30:48 · 1 answers · asked by ortegaphoto 1