Chemistry

penguincakes

We-yell the chemistry book classes esterification as a "condensation reaction" & this is in the organic reaction chapter.

d4r3n

Originally posted by claire h
Isn't it [H+] = sqrt[Ka + Macid]? The Ka is inside the square root, and that's how you get the H+ ions. I hope...

pH = -log10[H+]

H+ = sqrt(Ka * Ma)

ChemistryXpert

The PH was about 3. something,,,,,i think...


I think i got everything right....The organic bit was nice enough ,


methanol + propanoic ...that was the carbox and alco....


THe things i knew just came up especially in Q 4 where it is all your knowlege coming out ...liquefraction folllowed by fracional distill ,,,how nice...

By the way ,to remove mercury its electrostatic precipitation...


I made one blunder though ,is there anyone here who knows alot about how the paper is corected????????

MatthewVII

Originally posted by penguincakes
We-yell the chemistry book classes esterification as a "condensation reaction" & this is in the organic reaction chapter.

its in the organic section, but its not in the chapter "types of organic reactions". a condensation reaction can be undergone by any type of substance, inorganic or organic. the only three types of organic reactions on the course are substitution, addition and elimination, therefore its one of those three answers, and since the book says its a substitution reaction, thats the answer

MatthewVII

Originally posted by ChemistryXpert

By the way ,to remove mercury its electrostatic precipitation...

i myself said that mercury and other heavy metals such as lead are precipitated by using a dilute acid like HCl

Pb2+ + 2HCL -> PbCl2 + 2H+

ChemistryXpert

^^^Matt ,maybe you can help me...I made a terrible mistake,you know in the ethene exp ,i had the combustion and main equation correctly done and balanced but i had c2h2 instead of c2h4 ....But c2h4 was on the paper so it was just my mistake in writing it ,would the examiner let me away with it ,,,,its really buggin me.

penguincakes

Ah feck it anyway, I think I wrote substitution as well somewhere.

As for mixing up ethene with ethyne, hate to tell you but you probably won't get away with that... It can't just be a misreading cause it would imply you didn't understand it or something. I dunno.

ChemistryXpert

Everything was right and i knew ethene but i think i just wrote 2 hydrogens on the ethene instead of 4 ,,,that made it ethyne...but im just wondering about how it will be marked.

MatthewVII

it shouldnt be a problem, if you have the main equation correct then they'll realise that you just made a mistake in writing down the equation and that you meant to say C2H4. Notice that there are nine marks going for that question. 3 are going for the first part and 6 for the second. out of that 6, you would lose a maximum of 2 marks. that means that if youve gotten the rest of the question right, you'll still get an A1 for that particular question. Don't worry about it

ChemistryXpert

Thanks for the reassurance,its just its been drilled into us how heavy the marking is for chemistry that it was bugging me...It would be better if i didnt realise it then it would nt be playing on my conscience....