Science & Mathematics - 20 August 2007

1. when the tert-butyl chloride and HCl have been mixed into the separatory funnel, It must be shaken vigorously. Then, venting. What is the purpose of venting?

2. When the layers are clearly separated, drain the HCl layer into the beaker.
While the upper layer (raw tert-butyl chloride) is poured into the erlenmeyer flask. After that, dehydrate Calcium Chloride (CaCl2)are added to the raw tert-butyl chloride.

What is the function of dehydrate CaCl2?
Is it as a catalyst?
Does it reacts with the raw tert-butyl chloride?

3- Why primary and secondary alkyl halide are not synthesized during this method? Explain plz.

4- Why is the percentage of the yield in this experiment is less than 100%? Does the sample contains impurities? Explain.

Thanks for those who's answering me.
A lot of thanks

2007-08-20 20:33:06 · 2 answers · asked by Anonymous in Chemistry

1. We use activated charcoal in about the size of pea. What is its role in recrystallization? What happen if we add it too much??

2. Why filter funnel must be warmed before filtering the solution?

Hope u all can help..
Thanks

2007-08-20 20:20:42 · 2 answers · asked by Anonymous in Chemistry

plz give me the best answer,if your answer right.u have prize.surely!merC.

2007-08-20 20:19:39 · 10 answers · asked by ali_tulip67 1 in Other - Science

How many electrons are in a isotope Carbon 14 molecule?
I already know that there are 6 protons and 8 neutrons -plz plz help!

2007-08-20 20:12:19 · 5 answers · asked by rachelgrrl777 2 in Chemistry

... users could actually be able to reach out and touch one another "physically" as well, if they wanted to?

You know, sorta like a much more sophisticated physically-interactive version of a web cam; or do you think that is a total impossibility? ... And NO, I am NOT talking about any Matrix-like technology with the aid of which you might be able to biochemically simulate such a sensation, I am talking about literally being in the physical presence of the other party who maybe thousands of miles away.

[... I'm afraid it maybe passed my bedtime already! :-) ... Anyway, thanks for your comments.]

2007-08-20 20:08:28 · 9 answers · asked by Anonymous in Paranormal Phenomena

i just know it is to acidify the solution but can you explain in detail
thanks

2007-08-20 19:59:17 · 2 answers · asked by kev 2 in Chemistry

Would HeF7 be stable? Would there be any isomers possible? How could I find out bond angles?

I was trying to draw it but He only has 2 electrons on outer shell, and F has 7?

2007-08-20 19:54:32 · 2 answers · asked by chengdu 1 in Chemistry

2007-08-20 19:54:30 · 11 answers · asked by Favour 1 in Mathematics

find the LCM of (6+5p), (36-25p^2), and (6-5p)

2007-08-20 19:48:32 · 5 answers · asked by Anonymous in Mathematics

Leaving the Earth at the speed of Light and returning in the future doesn't seem to make sense at all.

How would traveling at the speed of light and leaving earth,and returning Be any Different than going 100 miles an hour, and returning.

2007-08-20 19:42:02 · 6 answers · asked by Anonymous in Physics

Ok, I know the correct answer is 8/3. But I CANNOT figure out how to do it. Can someone please help?!

Just to clarify, the question wants the integral of:
(x) (4-x^2)^2 OR
"x times the square root of 4 minus x squared", where b=2 and a=0.

2007-08-20 19:35:13 · 5 answers · asked by Anonymous in Mathematics

simplify by removing factors of 1
405u^9z^5/75u^4z^3

2007-08-20 19:34:25 · 2 answers · asked by Anonymous in Mathematics

you know, for special purposes. like when someone is trying to kill me. i jump behind them and hold the napkin over their face and they knockout. thanks ;)

2007-08-20 19:33:05 · 13 answers · asked by Anonymous in Chemistry

The speed of a train A is 10 mph slower than the speed of train B Train A travels 200 miles in the same time it takes train B to travel 250 miles. Find the speed of each train

2007-08-20 19:27:25 · 5 answers · asked by Anonymous in Physics

2007-08-20 19:21:41 · 4 answers · asked by Anonymous in Biology

if the presence of the ground point in the circuit provides an easy point of contact for someone to get shocked..

2007-08-20 19:18:33 · 3 answers · asked by Anonymous in Engineering

2007-08-20 19:17:50 · 5 answers · asked by M N 1 in Mathematics

2007-08-20 19:12:55 · 19 answers · asked by Prashanth 2 in Astronomy & Space

2007-08-20 19:10:04 · 18 answers · asked by Anonymous in Mathematics

A business manufactures two parts, X and Y. Machines A and B are needed to make each part. To make part X, machine A is needed 3 hours and machine B is needed 1 hour. to make part Y, machine A is needed 1 hour and machine B is needed 2 hours. Machine A is available 60 hours per week and machine B is available 50 hours per week. The profit from part X is $300 and the profit from Part Y is $250. How many parts of each type should be made to maximize weekly profit?

2007-08-20 18:57:53 · 2 answers · asked by Splendidy 1 in Mathematics

first measurement is 1.28, second measurement is 1.63...what percentage did the measurement increase by?

2007-08-20 18:47:05 · 5 answers · asked by mhovanes21 2 in Mathematics

just trying to get an idea of what it does to different people and how often they occur
Mine have included:
*Driving places I diddint remember going
*Sleep-walking/eating
*Making strange wierd foods at night
*Confusing my dog for a remote control (my husband told me)
*Painting my hardwood floors
*Thinking im in a place im not
*Seeing/hearing people or objects that arent there
*Nighttime amnesia
*No memory in the morning of what i did

Anyone elses story similar to mine

2007-08-20 18:36:59 · 9 answers · asked by durango_girl2747 2 in Medicine

please help

2007-08-20 18:32:10 · 8 answers · asked by Anonymous in Mathematics

the range for a normal resting heart is 60 to 90bpm.A trained athlete could have a resting heart of 45 to 60bpm.why might a very fit person have a slower heart rate than someone of average fitness?

2007-08-20 18:31:28 · 5 answers · asked by TO BE CONTINUED.... 2 in Medicine

x/x+9 - 9/x-9 = x^2+81/x^2-81.......thank you

2007-08-20 18:26:23 · 9 answers · asked by Anonymous in Mathematics

2007-08-20 18:24:49 · 15 answers · asked by VANESSA E 1 in Botany

http://www.youtube.com/watch?v=fSPzMva9_CE&mode=related&search=

2007-08-20 18:20:52 · 1 answers · asked by Luda R 1 in Astronomy & Space

I'm having a brain fart, and can't find the answer in any of my textbooks!

2007-08-20 18:20:38 · 4 answers · asked by lyridia 1 in Mathematics

2007-08-20 18:17:45 · 7 answers · asked by Anonymous in Mathematics

2007-08-20 18:14:47 · 4 answers · asked by xxbabycheekzix 1 in Mathematics