Chemistry - January 2007

My chemistry professor asked this in class, using vodka as the beverage of choice, probably because of its basic ingredients, but why does the 40% ethanol value not change overnight, especially with evaporation?

2007-01-24 16:56:49 · 4 answers · asked by paxdaddy32 2

Already, so you know how how as the atomic number increases the ration between amount on neutrons and protons increases. I was wondering if there is a general formula(not exact) to predict the ratio based on the atomic number.

2007-01-24 16:56:03 · 3 answers · asked by SuperImmortalKing 3

there is a explanation why do guys attracted to girls ...that can be explain through biology...

2007-01-24 16:54:05 · 4 answers · asked by Anonymous

2007-01-24 16:35:19 · 19 answers · asked by Smo 4

For all of you working in lab situations, especially us upper years, will get to handle more and more substances on our own. For us most recently we have been allowed to use liquid nitrogen for our research. It was a matter of seconds before the use liquid nitrogen was no longer limited to our research.

For example:
- we already tried freezing and smashing almost everything in the lab
- pouring into beer, mixing and trying to drink it (it turns out it freezes it too quick)
- pranks (we froze someones entire backpack just before he left to TA a lab; we tried filling a super soaker with it, unfortunately the expansion broke the gun apart but we managed to fire it once and it looked like a flame thrower shooting white gas!)

So those of you who also have worked with liquid nitrogen as well, what kinda fun stuff did you do? Maybe we'll try them out!

2007-01-24 15:55:29 · 11 answers · asked by Anonymous

I need help on my chemistry homework about binary compounds???
I need help matching these compounds. They can have the following names and the name can be used more than once!!

Here are the names you can use:
Binary Ionic
Binary Molecular
Ternary Ionic


Here are the compounds:
AlCl3
Ca(OH)2
KF
Pb(NO2)2
Ag2O
BaS
CO
CH4
(NH4)2S

2007-01-24 15:49:06 · 1 answers · asked by lyfe_has_hit_me 1

i have a chemistry question and i need some help, the question is,

a mole of B.B.'s would cover teh state of Ohio to what depth?

i all ready have the weight of a B.B. (.343 g) and the size of the state ohio 944,825 square miles) but i need to know what to do from there.

2007-01-24 15:44:00 · 2 answers · asked by sangel105 1

Aluminum(III) chromate
Iron(III) sulfate
Calcium nitrate
Silver(I)nitrate
Iron (III) hydroxide
Sodium Carbonate
Mecury (II) fluoride

2007-01-24 15:40:48 · 7 answers · asked by MELLY g 1

I'm having a really hard time figuring out conjugate acids and bases. This is the problem:

Write in the boxes formulas for the conjugate acids and conjugate bases of the following substances. If there is none, write 'NONE'.

HPO4 ^2-

HCO3 ^-

H2O (which I know can be either an acid or a base)

Cl^-

NH4 ^+

I don't know very much about chemistry, but I really want to learn how to work these. Any help you could give will be greatly appreciated.

2007-01-24 15:33:51 · 2 answers · asked by justinz_1fan 2

A solution of citric acid (a triprotic acid, C6H8O7) is prepared by dissolving 22.54g in water and made up to 500.0mL.

What is the molarity of this solution?

What is its normality?

When this acid solution is used to titrate a 25.00mL sample of NaOH, it takes 18.55mL acid to reach an end point. What is the molarity of the NaOH solution?

Sorry to bombard you with all these questions, but my chemistry teacher is horrible and he refuses to help me catch up after being out for a week (in the hospital). Any help or explanation you could give me would be wonderful.

2007-01-24 15:12:37 · 2 answers · asked by justinz_1fan 2

2007-01-24 15:03:06 · 2 answers · asked by Anonymous

An example please...and how hard is it?....I'm just curious.

2007-01-24 14:52:40 · 5 answers · asked by Anonymous

What are the pH values of the following solutions?

a) 0.15 M HNO3

b) 0.15 M NaOH

c) 1.5 x 10 (-3) M HNO3

d) 1.5 x 10 (-3) M NaOH

I know since HNO3 is 100% dissociated, you can calculate it straight out. Therefore, I think a is .82 and c is 2.82. I'm not sure if I'm right, however. I have no clue how to work b and d. If anyone could help, I'd be really grateful.

2007-01-24 14:44:17 · 2 answers · asked by justinz_1fan 2

2007-01-24 14:24:41 · 3 answers · asked by Anonymous

2007-01-24 14:17:22 · 9 answers · asked by Billy 2

Al+S8 yields Al2S3

Al(OH)3+HBr yields AlBr3+H2O

CH3CH2CH2CH3+O2 yields CO2+H2O

C2H6+O2 yields CO2+H2O

Al(OH)3+H2SO4 yields Al(SO4)3+H2O

H3PO4+Ca(OH)2 yields Ca(PO4)2+H2O

2007-01-24 14:14:44 · 3 answers · asked by †ღChristian♥Girlღ† 2

98.5 ml of milk at 21.0oC are added to 437.0 ml of coffee at 88.9oC . What is the final centigrade temperature of this liquid mixture when thermal equilibrium is reached ?


Assume coffee has the same properties as pure water.


The average density of milk is 1032 kg/m3


The specific heat of milk is 1.97 J/g-oC

2007-01-24 14:11:47 · 2 answers · asked by purple222 2

An FM radio station broadcasts at 97.0 MHz. Calculate the wavelength of the corresponding radio waves.
1.)____m

2007-01-24 14:11:00 · 2 answers · asked by Moe 2

2007-01-24 14:08:36 · 3 answers · asked by abi 1

2007-01-24 14:02:47 · 2 answers · asked by kyle k 1

Microwave radiation has a wavelength on the order of 1.0 cm. Calculate the frequency and the energy of a single photon of this radiation.
frequency

1.)Hz energy?
2.)J/photon?

Calculate the energy of an Avogadro's number of photons (called an einstein) of this radiation

3.) J/mol

2007-01-24 14:02:00 · 2 answers · asked by Moe 2

2007-01-24 13:56:49 · 3 answers · asked by kyle k 1

The work function of an element is the energy required to remove an electron from the surface of the solid. The work function for lithium is 279.7 kJ/mol (that is, it takes 279.7 kJ of energy to remove one mole of electrons from one mole of Li atoms on the surface of Li metal). What is the maximum wavelength of light that can remove an electron from an atom on the surface of lithium metal?


1.) mn?

2007-01-24 13:54:45 · 3 answers · asked by Moe 2

Please answer today becuz I need to present my science fair project tomorrow and itz really late (for me sins i hav 2 get up at 6!!!!)

2007-01-24 13:42:06 · 3 answers · asked by racecar2daendofdastreet 1

I kno wat polar and nonpolar bonds are, but what r the compounds. Plz make your answer clear if u want your answer to be chosen as Best answer....i have midterms tommorow ..plz help

2007-01-24 13:38:49 · 3 answers · asked by tkdgrl01 1

2007-01-24 13:36:48 · 4 answers · asked by Sunshine 1

Need help with one of the question... on denstiy.. thank you


An ice cube with a volume of 50.0ml and a density of 0.8 g/cm3 floats in a liquid with a density of 1.30 g/ml. What volume of the cube is submerged in the liquid?

2007-01-24 13:34:58 · 4 answers · asked by Anonymous

68.5 grams of a certain compound contains 5.25*10^25 molecules. What is the molar mass of the compound?

I don't know how to start the conversion. Can somebody please give me the conversion factors? Thank You.

2007-01-24 13:32:31 · 5 answers · asked by Anonymous

what is the product of the following chemical equation?

Ca + HCl --->

2007-01-24 13:16:38 · 3 answers · asked by alexandra1579 2

Thanx Guys for all your help..CHemisty is killing me

2007-01-24 13:16:01 · 4 answers · asked by Anonymous