Chemistry - December 2007

1) If the average velocity of Helium (molecular weight=4g/mole) is 0.707miles/second at room temperature, what will be the average velocity of oxygen(molecular weight 32g/mole) at the same temperature?

2)A gas of unknown composition diffuses at the rate of 10ml/sec in a diffusion apparatus in CH4 (molecular weight=16g/mole) gas diffuses at the rate of 30ml/sec.Calculate the molecular weight of the unknown gas.

please help me answer as much as possible. I have a final on monday =( thanks in advance!

2007-12-14 05:29:08 · 2 answers · asked by Heart You 3

Can you make it with baking soda?

2007-12-14 05:22:07 · 2 answers · asked by Anonymous

Water is heavier than air but in its water vapour state it float and rises as clouds and stay afloat trillion of tons of it? Why? What physic explanation is there for it scientifically? It bewildered me.

2007-12-14 03:52:36 · 10 answers · asked by Anonymous

help me i need this for my science question

2007-12-14 02:48:09 · 5 answers · asked by xxrandomazngurlxx 1

Was told to get the alkalinity adjusted first. Then adjust the pH. When I get the pH right, then the alkalinity is low. When I get the alkalinity right, the pH is too high. Can't seem to get a good balance of both. By the way, I use Bromine for a chlorinator.

2007-12-14 02:32:00 · 2 answers · asked by ringerman50 1

2007-12-14 02:15:44 · 3 answers · asked by Anonymous

I need help, I don't understand this at all! I want to use Orange Juice. So what do I do? Ten points to the first person that can help me!

Find the hydrogen ion content of a substance of your choice.
Using this hydrogen ion content, show how to find the pH of the substance using the formula. Is this substance acidic or basic? Why?
Round the pH to three decimal places.

2007-12-14 02:12:42 · 1 answers · asked by cupnnas2002 3

I get that the MandleCandle uses patented microelectronic technology driven by heat from an environmentally friendly Lithium battery, BUT HOW? Does it rely on different densities of differently coloured waxes/fluids...bit like a lava lamp? I've only seen them on telly, so I wouldn't know! Ta! x

2007-12-14 00:52:06 · 5 answers · asked by Anonymous

2007-12-14 00:47:40 · 3 answers · asked by U Betcha 6

1
A swimming pool that is 3.05 m wide by 6.10 m long has an average depth of 2.75 m. The density of water is 1.00 g/cm^3. What is the mass of water in the pool when it is filled?
2
One barrel of crude oil weigh 0.136 metric tonnes . A metric tonne is exactly 1000kg. A barrel has a volume equal to 158.98 L. What is the density of crude oil in g/ ml?
3
The density of coconut oil is 57.7 puonds/ft^3. What is the value in g/cm^3? The fallowing relation are exact; 1 ft =12 in = 2.54 cm, 1 pound = 453.6 g.

2007-12-13 23:46:44 · 2 answers · asked by Math help me 1

If you don't know them all you can just explain or solve the ones you know. I really really need help.

1
The density of diamond is 3.51 g/cm^3 and a graphite is 2.22g/cm^3. Both substance are pure carbon. What volume, would 10.0 g of carbon occupy
a) In the form of diamond?
b) In the form of Graphite?

2
The mass of the sun is 1.991 x 10^30 kg and the density of the sun is 1.41in the 0 g/cm^3. What is the volume of the sun in m^3?

3
The mass of the Earth is 5.979 x 10^24 kg and the density of the earth is 5.519 g/cm^3. What is the volume of the Earth in m^3?

4
Under certain condition, the density of dry air is 1.205 g/L. What is the mass of the air in a room that is 3.658 m wide by 4.572 m long by 2.438 m high?

2007-12-13 23:38:00 · 4 answers · asked by Math help me 1

what is the product of this reaction ( aminoacetonitrile + cyanic acid)????? can you plz help me in this???

2007-12-13 22:48:53 · 5 answers · asked by Anonymous

2007-12-13 21:38:45 · 3 answers · asked by charisz 2

Neon-?

Iodine-?

Selenium-?

2007-12-13 17:55:17 · 3 answers · asked by Istis 3

2007-12-13 17:50:59 · 3 answers · asked by Anonymous

1.explain why each of the follwing pairs is not lieky to form an ionic bond.
a. chlorine and bromine
b. potassium and helium
c. sodium and lithium

2007-12-13 16:48:36 · 6 answers · asked by LumpiaEATER ! 2

If families share similar properties, how is it possible that metals, nonmetals, and metalloids are in the same family? thanks : )

2007-12-13 16:38:16 · 2 answers · asked by Anonymous

which of the following compounds conains the Mn3+ ion?

A. MnS
B. MnBr2
C. Mn2O3
D. MnO

2007-12-13 15:38:11 · 2 answers · asked by basketballrules420 1

I have a list of formulas such as MgO, Na*subcript 2*O, H2O, etc., but I have no idea how to figure out what formulas are ionic compounds.

2007-12-13 14:48:29 · 3 answers · asked by ABC Puppy 3

Do you know any chemical equations that has to do with this career?
Thanks for the help!

2007-12-13 14:37:28 · 2 answers · asked by J.A. 2

1) 21. 23.45 mL of 0.275 M sodium hydroxide was used to titrate against mL of acetic acid. What was the concentration in M of acetic acid?

2) 24. 24.92 mL of 0.00199 M silver nitrate was used to titrate against 5 mL of sodium chloride solution. What was the concentration of NaCl?

3) 23. 35.79 mL of 0.275 M sodium hydroxide was used to titrate against 15 mL of sulfuric acid. What was the concentration in M of sulfuric acid?

please explain how you did it, thanks.

2007-12-13 14:22:42 · 2 answers · asked by Anonymous

I have to do this game board project and my board is going to be the periodic table. Each element is a different space. I need ideas for how to move up spaces on the note cards. For example, one might be your atomic mass increased, move up 2 elements.

2007-12-13 14:09:18 · 2 answers · asked by don 2

a 0.562 g sample of an unkown substance was dissolved in 17.4 g benzene. the freezing point of the solution was 4.075 degrees celcius. the freezing point of pure benzene is 5.455 degrees celcius. for benzene, Kf=5.065 degrees celcius/m and Kb=2.61 degrees celcius/m. assume that the solute is a non-electrolyte.

a. what is the molality of the solution?
b. what is the molar mass of the unkown?
c. if the boiling temperature of pure benzene is 80.2 degrees celcius, what is the boiling temperature of the solution?
d. what is the van't Hoff factor? explain whether one was neccessary in these calculations

2007-12-13 14:05:45 · 3 answers · asked by confusedkid 3

I'm in college and I struggled to get a C+ in chem 1. I thought I had a pretty good grasp of it but I just can't understand electron shells and all that stuff. As far as we went was 3d electron diagrams, tetrahedrals, trigonal bipyramidal etc.

Could I handle chemistry 2? I registrered for it next sem. but I don't know anymore, does it get much more complicated?

2007-12-13 11:39:45 · 3 answers · asked by Anonymous

the question is like this:

"The empirical formula for a compound is C2H3As3Cu2O8 with a molar mass of 1013.71g. What is the molecular formula?"

i dont understand how you to find the molecular formula here -_-

2007-12-13 11:29:29 · 7 answers · asked by Anonymous

??

2007-12-13 11:28:43 · 5 answers · asked by Optimus Prime 2

are B+'s good???

2007-12-13 11:28:14 · 10 answers · asked by iHeartChem 2

OK WELL
IM STUDYINBUT I DONT REALY UNDERTAND IDEAL MACHINES

Work in = W ork out

I DONT GE THTAT HELP ME !!!!!!!

2007-12-13 11:21:40 · 2 answers · asked by :}smile :} 1

2007-12-13 11:11:25 · 0 answers · asked by Anonymous

2007-12-13 11:09:49 · 3 answers · asked by Anonymous