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post away....
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Posted: 2006-03-09 06:45:21
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Hey i wll do later a soon as i get back from college this afternon, really appreciate this.
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Posted: 2006-03-09 07:33:46
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you big lazy cheater! You should be hounded out of Esato, and college! In my day...
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Posted: 2006-03-09 11:11:36
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It is not like they are homework as such there just practice questions for the real thing if i can make sure i can get the right answers for these then i can apply the working out to everything else.
Really need to get the hang of chemistry i have never done any in school apart from a few stupid experiments never done calculations before and the teacher doesn't explain things very well.
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Posted: 2006-03-09 13:48:29
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ARG!!! I have had alot of questions to do in chemistry, around 25 and i have managed to do all of them, by some miracle, apart from these, don't suppose anyone could help me out?
1. The rate equation for a reaction A + B ? products was found, by experiment, to be:
Rate = 0.26 x [A]x[B]2
A) State the order of reaction with respect to A and to B. What is the overall order for the reaction?
B) What would be the increase in rate if the concentrations of both A and B were doubled at the same time? I THINK THIS IS TIMES BUT I HAVE NO IDEA WHY?
C) Calculate the expected reaction rate if [A] = 0.16 mol dm-3 and [B] = 0.32 mol dm-3
2. An acid buffer solution is an aqueous solution of a weak acid (HA) and it’s sodium salt (NaA)
I) Explain why there is only a small pH change when a small volume of acid is added to this buffer solution.
II) Given that the pKa value of HA is 4.35, what will be the pH of a buffer solution that contains 0.35 moles of NaA and 0.25 moles of HA?
3. Give the chemical formulae of the products formed when ethane (CH2=CH2) and propene (CH3CH=CH2) react with each of the following:
A) H2 with Ni catalyst
B) Bromine Br2
C) Hydrogen bromide, HBr
D) What product forms when the products of reactions B and C react with aqueous sodium hydroxide, NaOH?
4. Two alcohols are CH3CH2CH2OH and (CH3)2CHOH (propan-1-ol and propan-2-ol)
Give the formula of the products formed when each alcohol reacts
with ethanoic acid (CH3COOH). To what class of organic compound
Do these products belong?
What are the oxidation products of these alcohols? Explain how the oxidation products could be used to distinguish between these alcohols by means of a chemical test.
Would really appreciate it, this is the last thing ever for chemistry then it is over, thank god!
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[ This Message was edited by: miss copperfield on 2006-05-22 09:37 ]
[ This Message was edited by: miss copperfield on 2006-05-22 09:38 ]
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Posted: 2006-05-22 09:58:51
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1.
A) 1 and 2 resp. total order 3
B) 8
C) Substitute values
2.
A) Thats what a buffer is suppposed to be. Adding of H+ will shift equilibrium backwards and the H+ will be consumed hence little ph change.
B)pH = pKa + log(moles of NaA/moles of HA) Put values and solve
3.
A) syn addition of 2 H across the double bond
B) anti addition of 2 Br across the double bond
C) CH3-CH2Br and CH3CHBr-CH3
D) replace Br groups with OH
4.
CH3CH2CH2OCOCH3 and (CH3)2CHOCOCH3. Both Esters
On oxidation Acid and Ketone resp. Do any test for acids to distinguish eg do sodalime decarboxylation and test for CO2 with lime-water.
I'm really sleepy at the moment so sorry if there are any errors as i'm trying to rush through this...
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Posted: 2006-05-22 22:10:33
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Oh clank i love you, thank you so much you are a genius!!!
Much much much much appreciated!!!
Thanks!!!
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Posted: 2006-05-22 22:48:28
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I'm Back!
Ok so i have two assignments due on tuesday before i finish my course and i have near enough finished one but i cannot find the answers to the following;
1.
The chlorides of sodium and phosphorus are Na2O, NaCl, P4O10 and PCl3, state what bonding is present in each compound?
2.
Classify the oxides as either acidic or basic and give equations that show what happens when they are added to water?
3.
Give equations that show what happens when NaCl and PCl3 are added to water?
I can find various bits and bobs through google but nothing conclusive, can anybody recommend a decent chemistry site all the ones i have find are very clogged with loads of information.
I am also stuck on a few other things if anybody can help me out then pop me a pm, god i hate this subject why the hell i choose it i will never know.
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[ This Message was edited by: miss copperfield on 2006-06-16 19:18 ]
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Posted: 2006-06-16 20:15:09
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