Chemistry - May 2007

2007-05-01 16:52:01 · 1 answers · asked by sarah j 1

what is the major alkene product for dehydration of 1,2-cyclohexanediol? is it something related to keto-enol?

2007-05-01 16:34:22 · 2 answers · asked by Sandy 2

If a 8.90 lb cat absorbs 4.90 × 10−6 KJ of radiation, how many rads did this cat absorb?

2007-05-01 16:34:03 · 1 answers · asked by Richi C 1

1. A chemists determines that a sample of petrified wood is 4.50 X 103 years old. What is the rate of decay, in counts per minute per gram, of carbon-14 in the sample? The decay rate of carbon-14 in wood today is 13.6 counts per minute per gram, and the half life of carbon-14 is 5730 years.

2. Capture of an electron by iron-55 produces what new element or isotope ?

2007-05-01 16:27:36 · 1 answers · asked by Yessica 1

Need an answer check...A gas has a volume of 269 mL at STP. Wht Celsius temperature will cause the gas to have a volume of 190 mL at a pressure of 182 kPa?

P1V1T2 = P2V2T1

2007-05-01 16:11:08 · 3 answers · asked by jodyboy17 2

Alright so I need to calculate the total pressure in the container. Here is the info I have.
1.702307307 mol
200.0 g
50.0 L
800 C

Okay so I know I use PV=nRT but I only have the n, V, and T so for my R do I just use the 8.31 thing.



Also...
On another problem it says "What volume of gas is formed at STP by the decomposition of calcium carbonate with heat?" It doesn't give any data so I don't know what to do?? I have the balanced equation
CaCo3= Co2 +CaO

Any help you can give....Thank you.

2007-05-01 15:52:40 · 4 answers · asked by Jennifer 1

2007-05-01 15:49:13 · 2 answers · asked by Anonymous

1) The conjugate acid of CH3COOH is _________ ??

2) Calculate the pH of 1 x 10^-8 M HCl. (The pH cannot be 8, right?)

Thanks a lot!!!

2007-05-01 15:46:33 · 6 answers · asked by Anonymous

2007-05-01 15:45:33 · 1 answers · asked by giggles9783 1

which of the following statements is true ?

a) the mass number is 13
b) the atomic mass is 15
c) the atomic number is 12
d) the mass number is 25

2007-05-01 15:38:32 · 7 answers · asked by classy.chic 3

Does it decrease the average kinetic energy of the reactants of the reaction?
Does it increase the chance reactants will collide in the proper orientation?
Does it decrease the threshold energy value with which two particles must collide?

Or does it do something completely different?

Thank you in advance for your help!

2007-05-01 15:18:14 · 7 answers · asked by Random G 3

A reaction mixture contains 14.3 g of PCl_3 and 9.10 g of PbF_2. What mass of PbCl_2 can be obtained from the following reaction: 3PbF_2 + 2PCl_3 yields 2 PF_3 + 3PbCl_2. What mass of PF_3 is formed? What is the mass of the excess reactant? Please, Please, Please show steps. Thank you.

2007-05-01 15:14:05 · 1 answers · asked by me of course 2

a) a proton and a neutron
b) a nucleus and two electrons
c) an electron orbiting a proton
d) an electron, neutron, and proton

2007-05-01 15:11:14 · 6 answers · asked by Anonymous

If a 3.30 lb cat absorbs 1.40 × 10−5 KJ of radiation, how many rads did this cat absorb?

2007-05-01 15:09:04 · 2 answers · asked by asiansenz 1

2007-05-01 15:03:53 · 5 answers · asked by Random G 3

1.) Sound cannot travel through which of the following mediums?
A. vacuum B. solid C. gas D. liquid

2. The slower the vibrations, the _____ the pitch.

A. higher
B. louder
C. slower
D. lower

2007-05-01 14:56:48 · 6 answers · asked by Anonymous

i'm having trouble understanding this concept.
for example, why is HF a weak acid, and why is HNO3 a strong one?

2007-05-01 14:55:38 · 3 answers · asked by alexie. 4

Sound is caused by:

A. ticking
B. atmosphere
C. vibrations
D. pitch

2007-05-01 14:54:36 · 6 answers · asked by Anonymous

Capture of a neutron by nickel-60 produces a proton and what new element or isotope ?

2007-05-01 14:48:22 · 1 answers · asked by Anonymous

Explain the following properties of solids by describing what is occuring at the atomic level-
1)Metallic solids conduct electricity well, but covalent network solids do not.
2) Amorphous solids do not have a definite melting point.
3)Ionic crystals are much more brittle than covalent molecular crystals.

-I missed class the day they were learning this stuff, so if you can answer any of these 3 questions,...thank you

2007-05-01 14:45:30 · 1 answers · asked by Anonymous

2007-05-01 14:45:06 · 3 answers · asked by W 1

Predict the ordering of the boiling points of the following:
(i) CH3—O—CH3 (ii) CH3CH2OH (iii) CH3CH2NH2

I need some help figuring this out. Also show the steps taken to get the answer. Thanks

2007-05-01 14:37:38 · 2 answers · asked by nglennie_06 1

Estimate the melting point of an unknown substance in deg C if the latent heat of fusion of the substance is 1.06 kJ/mol and the entropy change for the change in state of the substance from solid to liquid at its melting point is 18.40 J/K.mol.

2007-05-01 14:37:00 · 2 answers · asked by smokefanTS20 3

2007-05-01 14:18:16 · 3 answers · asked by Anonymous

2007-05-01 14:04:27 · 6 answers · asked by Brendan 2

the question is. write a formula equation for the reaction between aqueous silver nitrate and copper metal to yield silver metal and aqueous copper(II) nitrate. PLEASE HELP

2007-05-01 14:02:26 · 2 answers · asked by Divine 2

I'm struggling with chemsity, and I really need help. Does anyone know how to do this problem? Please only answer if you're somewhat aware of how to do this.

"A sample of gas at constant volume has a pressure of 7.5 ATM and a temperature equalto 25 degrees Celcius. What will the pressure be in mmHg when the temperature increases to 50 degrees Celcius? "

2007-05-01 13:51:05 · 1 answers · asked by Anonymous

2007-05-01 13:45:40 · 2 answers · asked by au91 1

How would I get my ti 83 to solve this problem. 1.5e-9=x^2/(.5-2x) I need major help.

2007-05-01 13:45:26 · 1 answers · asked by naweb230 2

I'm stuck on this problem in chem,, I balanced the equation but am not too sure as to what I'm supposed to do now. Here's the problem and equation:

Methane is burnt in oxygen to produce carbon dioxide and water vapor. The final pressure of the gaseous products was 6.25 torr. Calculate the partial pressure of the water vapor.

CH4 + 202 --(heat)--> CO2 + 2H20

...now what? Can anyone help?!?

2007-05-01 13:45:08 · 1 answers · asked by alex 1