Chemistry - August 2007

2007-08-08 01:34:40 · 6 answers · asked by Anonymous

2007-08-07 22:59:50 · 7 answers · asked by Topnut 2

2007-08-07 22:38:47 · 5 answers · asked by nawizo87 1

2007-08-07 22:35:31 · 1 answers · asked by Anonymous

I can't find an ansewer for this question in the web. Can anyone help me????? Please..... This is a part of my homework in Chemistry............... please..... I need help.....

2007-08-07 19:40:47 · 2 answers · asked by chrisbel r 2

Radioactive copper-64 decays with a half-life of 12.8 days.
(a) What is the value of k in s-1?
(b)A sample contains 28.0 mg Cu-64. How many decay events will be produced in the first second? Assume the atomic mass of Cu-64 is 64.0.

For part (a) I calculated K as .000000627 1/sec
I don't know what a decay event is and I can't figure it out in my textbook or online. If someone could please explain to me what a decay event is (is it the amount of times the balaned reaction goes to completion? is it the number of Cu atoms that decay?)

Also if you could show me how to solve part (b) or at least give me the equation you used and answer. It must be in units of decays/s. I'm assuming you use the equation ln(N/No)=-kt

Any information at all that you can give me will be extremely helpful! Thank you so much!

2007-08-07 19:34:29 · 1 answers · asked by alice 2

How many grams of zinc chloride could be formed from the reaction of 4.96g of zinc with excess HCl?

2007-08-07 18:34:35 · 2 answers · asked by Nicole J 1

2007-08-07 18:26:04 · 5 answers · asked by MSK 1

How do you find the ionic equation for this?

3 BA (NO3)2 (aq) + 2 Na3PO4 (aq) --> Ba3(Po4)2 (s) + 6NaNO3 (aq)

2007-08-07 18:17:59 · 2 answers · asked by Vienna 3

A calorimeter contained 75g of water at 16.95C. A 93g sample of iron at 65.58C was placed in it, giving a final temperature of 19.68C for the system. Calculate the heat capacity for the calorimeter. Specific heats are 4.184 for water and 0.444 for Fe.
The answer is suppose to be 381J/C but I dnt know how it was derived, can anyone explain the answer?

2007-08-07 17:43:50 · 1 answers · asked by Mr S 2

2007-08-07 16:46:27 · 5 answers · asked by dov20051 3

I need to add .1ml of 0.1N HCL but I don't know what 0.1 N is. I have plenty of stock solution 38% HCL. How do I make .1 n out of 38%?

2007-08-07 16:23:44 · 11 answers · asked by Anonymous

Just something that i have been wondering. 15 ml is also 1/2 oz.. if that helps!

2007-08-07 16:19:12 · 2 answers · asked by Anonymous

If any one could answer any of these questions it would be of great help!
What is the role of equilibrium in the production of ammonium?
What are the factors required for the economical commercial production of ammonium?
What impacts would a chemical plant using the haber process have on the surrounding environment and how could this be controlled?
Thanks for your help =)

2007-08-07 16:10:41 · 1 answers · asked by Emily =) 1

Thalidomide has two distinct forms. One form (1) acts as sedative and sleep aid whereas the other (2) causes terrible birth defects. Strangely, both have the same chemical formula, C13H10N2O4. The differences between the two are entirely due to the different arrangement of the atoms in space.

Why two molecules with the same chemical formula may still have different connectivity and geometries?

2007-08-07 14:48:31 · 3 answers · asked by Leo 1

I was looking at a gold bar from Switzerland and saw the price. I am not a gold collector but thought about investing money in small gold ingots once a year.

Thanks to al in advance for answering with real information and not unrelated answers.

2007-08-07 14:45:04 · 0 answers · asked by HA! HA! HA! 5

I wouldn't ever do this but I was curious what would happen?

2007-08-07 13:31:46 · 9 answers · asked by justask23 5

a compound used in electroplanting? Explain ypur reasoning.

2.Use the terms PH bond indicator to describe a way to determine whether an unkown solution is acidic or basic.

3.What mass of water is required to absorb 4.7 times 10*5 J of energy from a car engine while the temperature increases from 298k to 355

*5 is small and goes on the side of 10

2007-08-07 13:27:17 · 2 answers · asked by Anonymous

2007-08-07 13:17:35 · 3 answers · asked by poonam 1

2007-08-07 13:14:23 · 2 answers · asked by poonam 1

i have a 1 gallon bucket ,if i fill it with soduim bicarbonate how much will it weigh?

2007-08-07 12:28:22 · 2 answers · asked by tie003uk 1

an equation for the reaction of semicarbazide with acetophenone to form semicarbazone. what's the melting point of this derivative?

2007-08-07 12:20:50 · 1 answers · asked by mela 1

2007-08-07 12:16:38 · 1 answers · asked by trippkim 1

Al(OH)3 + HClO4 ==== ???????


"Solid aluminum hydroxide is added to perchloric acid" to form wat????

PLEASE ITS THE LAST PROBLEM BEFORE I SEND OFF THIS ASSIGNMENT THANKS

2007-08-07 11:49:29 · 3 answers · asked by hillybilly135 1

heres another chem question im having trouble on...thank you so much~

A 750. mL solution containing potassium bromide is evaporated to dryness and 133.74 milligrams of solid potassium bromide are collected. What was the molarity of the original solution?
(answer in moles)

2007-08-07 11:31:06 · 2 answers · asked by Anonymous

2007-08-07 10:52:07 · 2 answers · asked by Anonymity 3

can you name some triprotic acids?

i know H3PO4 is one but thats not what im looking for...
know any more?
thx

2007-08-07 10:44:29 · 2 answers · asked by Anonymous

2007-08-07 10:37:36 · 3 answers · asked by Vienna 3

2007-08-07 08:28:03 · 3 answers · asked by surgeon1121 1

I know graphite is carbon, but any other differences? I read somthere that a carbon electrode uses less power. Is this true? In electrolysis, does one produce more H or O2 than the other or does one do it faster?

2007-08-07 06:34:12 · 1 answers · asked by Dan S 2