Chemistry - April 2007

Choices: 1.) [Co(NH3)6]3+ 2.) [Co(CN)6]3- 3.) [Co(ox)3]3- 4.) [CoCl6]3- 5.) [Co(OH2)6]3+

2007-04-27 09:05:59 · 1 answers · asked by haji_kwang 1

Capture of an electron by argon-37 produces what new element or isotope ?

2007-04-27 09:01:15 · 2 answers · asked by Foxychick 1

2007-04-27 09:00:12 · 2 answers · asked by afchica101 1

For a first order reaction the rate R = −k N so the ratio of rates at two different times is given by R(t1)/R(t2) = N(t1)/N(t2).

For nuclear decay the rate is ofen is expressed in units of counts per unit of time.


A chemists determines that a sample of petrified wood is 2.50 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.


Enter a numeric answer only do not include units

2007-04-27 09:00:07 · 2 answers · asked by Foxychick 1

2007-04-27 08:01:24 · 6 answers · asked by Anonymous

2007-04-27 07:50:41 · 2 answers · asked by Anonymous

2007-04-27 07:39:40 · 1 answers · asked by Lin Tong F 1

a. 33.6g
b. .589g
c. 15.6g
d. 1.77g

2007-04-27 07:32:36 · 3 answers · asked by azmlb1 1

if 2.57g of the citric acid (C6H8O7, MW=192g/mol) reacts with the excess sodium bicarbonate (NaHCO3), how many grams of CO2 (MW=44g/mol)....? background info: antacids such as alka-seltzer, use the reaction of sodium bicarbonate with citric acid in water solution to produce a fizz as follows: 3NaHCO3+C6H8O7---> 3CO2+3H2O+Na3C6H5O7.

2007-04-27 07:27:20 · 2 answers · asked by azmlb1 1

2007-04-27 07:14:33 · 5 answers · asked by sandysdachshund 3

When heated, solid KClO3 forms solid KCl and O2 gas. A sample of KClO3 is heated and 226 mL of gas with a pressure of 749 mm Hg is collected over water, at 26°C. At 26°C, the vapor pressure of water is 25 mm Hg.

2KClO3(s) → 2KCl(s) + 3O2(g)

How many grams of KClO3 were reacted?

2007-04-27 07:01:38 · 3 answers · asked by Anonymous

I have a very heavily weighted question for my bio-chem class. We have to discribe the pathways of digestion on a cellular leavel. For example glycolisis....any help would be AWSOME.

2007-04-27 06:48:50 · 3 answers · asked by mbrilts 2

You have covered a grounded metal surface with a layer of photoconductor. Working in the dark, you sprinkle negative charge onto this surface. If you now expose only the left half of the photoconductor to light, you will find that (Select one)


A) nothing happens because there is no changing magnetic field.

B) the right half becomes neutral while the left half remains negatively charged.

C) negative charge flows from the right side of the photoconductor to the left and both sides become neutral.

D) the left half becomes neutral while the right half remains negatively charged.

Why?

2007-04-27 06:46:03 · 1 answers · asked by freepeopleurbangirl34 1

the ending is supposed to be: & burned as fuel in the body?

2007-04-27 06:41:30 · 3 answers · asked by lar5936 1

I know exactly what reactions i am going to do to identify the compounds:-
bromoethane - silver nitrate test
butan-1-ol - acidified potassium dichromate
cyclohexene - bromine water
ethanoic acid - sodium carbonate
methlypropan-2-ol - potassium dichromate
water - anyhydrous copper II sulphate

But the problem i have is how do i do the flow chart? I don't know what will react with what, so i don't know what test will eliminate what!! We do not have time to do the whole investigation at school so does anyone no the results, or how the flow chart should go? Any help would be greatly received!!

2007-04-27 06:39:10 · 1 answers · asked by Anonymous

If I compare Cu and Zn from the periodic table,
Cu--3d10, 4s1 -- means can easily loose e, thus should undergo oxidation easily.
Zn --3d10, 4s2---full valence shell, therefore loosing e is not easy, therefore shouldnot undergo oxidation.
But in real electrochem cells Zn undergoes oxidation instead of Cu. Why?
Also, I compared Cu and Ag--4d10 5s1--Ag being bigger in size should loose electons easily as compared to Cu and should undergo oxidation easily, but this is not observed. Infact, Ag undergoes reduction in presence of Cu.
I am also aware of the table of strong reducing agents. Zn is placed higher than cr, Ni,Cu, Ag. But I fail to understand how is this table arranged? I tried to find a "link" between this table and the periodic table or the distribution of the valence e. It is not making much sense to me.
Li, K, Ca etc are on the left of periodic table and are good reducing agents=undergo oxidation=loose e.
Also Cu is on the left of Zn then why it doesn't undergo oxd?

2007-04-27 06:15:25 · 1 answers · asked by AS 1

Doing a very important scientific experiment in chemistry and I require this on priority..please..help..

2007-04-27 06:12:58 · 8 answers · asked by rejash 1

2007-04-27 06:03:54 · 3 answers · asked by Sophia M 1

2007-04-27 05:57:18 · 9 answers · asked by sandysdachshund 3

and a saltine wrapper

2007-04-27 05:03:16 · 1 answers · asked by dead eye 1

2007-04-27 04:53:51 · 2 answers · asked by YAHOO_USER__ 1

Can someone please work through this problem with me:

For a first order reaction the rate R = −k N so the ratio of rates at two different times is given by R(t1)/R(t2) = N(t1)/N(t2).
For nuclear decay the rate is ofen is expressed in units of counts per unit of time.


A chemists determines that a sample of petrified wood is 5.00 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.

2007-04-27 04:43:53 · 1 answers · asked by Djuna 2

do you agree with his/her view?
If not, how could you prove that the temperature only changes the colour of a solution when it changes the concentration of one or more of the coloured species in the solution? Suggest an experimetal set-up.

2007-04-27 04:24:31 · 1 answers · asked by LOVELEYG R 1

i have a question with lambda = mean free path and it says at what pressure does the mean free path of argon at 25 celculis become comparable to 10 times the diameter of the atoms themselves with o=0.36nm^2?

****and then in the answer it says diameter = (0.36nm^2/1)^.5 but then they get the answer 3.39x10^-10 is the equation wrong i think it has something to do with being divided by 1? i dont think im reading it correctly. can someone tell me this expression for diameter of an atom? thanks

2007-04-27 03:45:56 · 1 answers · asked by bunnylover1987 1

2007-04-27 03:37:48 · 2 answers · asked by Yoan 1

Working in the dark, you sprinkle negative charge onto this surface. If you now expose only the left half of the photoconductor to light what will happen?

2007-04-27 02:53:02 · 1 answers · asked by Anonymous

The initial reaction in an automobile airbag is : 2NaN3(s) → 3N2(g) + 2Na(s)

How many liters of N2 at 25.0oC and 1.00 atm. result when 105grams of NaN3 react?

2007-04-27 00:56:31 · 3 answers · asked by JULIO C 1

What are the atomic number, mass number and element name of the product when:

A. An isotope of atomic number 95 and mass number of 241 undergoes emission of an alpha particle.

B. An isotope of atomic 27 and mass number 60 undergoes gamma emission.

2007-04-27 00:55:43 · 2 answers · asked by JULIO C 1

32P has a half life of 14.3 days. If initially there are 50.0g of it, how many grams of it remain after times of

A. 14.3 days

B. 28.6 days

C. 42.9 days.

2007-04-27 00:54:50 · 2 answers · asked by JULIO C 1

Aliquots of a 0.5 mg/mL standard of BSA were used to construct a standard curve for the Bradford protein assay. The tubes contained the following amounts of the BSA solution: 0, 20, 40, 60, 80, and 100 µL. the corresponding absorbance after adding Bradford reagent were the following: 0, 0.05, 0.09, 0.14, 0.19 and 0.22. If you took 20 µL of an unknown and added 80 µL of water, mixed, took 10 µL of the mixture, added this to the Bradford reagent, and saw an absorbance of 0.08, what was the protein concentration of the undiluted unknown?

2007-04-26 23:41:19 · 1 answers · asked by Anonymous