Chemistry - General Thoughts (1 Viewer)

[richz]

no it asked for Total dissolved solids, so it shud have been the amount in the evap basin

 

[stef.]

no it asked for Total dissolved solids, so it shud have been the amount in the evap basin

yeh..but by mixing it with water..then filtering and drying the filtrate..the whole experiment is working towards dissolved solids..
its just taht after drying it..shouldnt the mass have decreased..not increased..or where the filtering part and drying part separate??

 

[stef.]

basin thing weighed more than the filter paper so yeh...

after u minus the weight of the filter paper from the filter paper and solid you get 0.03..and after u minus the weight of the evap basin from the evap basin and solid u get 0.26..i just though that was fishy... =]

 

[richz]

no i dont think so, it says total dissolved solids, so u just calc the difference between the basin and basin + wats inside. When ur filtering u measure suspended solids, so those are not dissolved solids, are they

 

[Homercles]

What about that 7 marker with the flow chart? I thought they should have given us more space, I didn't expect to have to cram an esterification diagram into the margin!

 

[stef.]

no i dont think so, it says total dissolved solids, so u just calc the difference between the basin and basin + wats inside. When ur filtering u measure suspended solids, so those are not dissolved solids, is it?

ohhh..i get it now..after ive answered the question..ironic..
im glad i went with evap basin number

 

[stef.]

What about that 7 marker with the flow chart? I thought they should have given us more space, I didn't expect to have to cram an esterification diagram into the margin!

i absolutely agree..but i guess theyre looking for the ppl who can write succinctly and concisely w/o waffling..and i drew my diagram in the margin..i dont think u can actually work out what it is cos its so crammed.

 

[~SeXcSuM~]

how do u work out the percentage of the TDS though? u have to put the amount of TDS left over something and times by 100... i have no idea

 

[richz]

i think, and again this is my view

(amount/500g) *100

i got a very low answer

 

[stef.]

same

(10 char)

 

[chooette]

Thats what I got, i think its right... 0.052% or something looking like that maybe?

 

[queenie]

i absolutely agree..but i guess theyre looking for the ppl who can write succinctly and concisely w/o waffling..and i drew my diagram in the margin..i dont think u can actually work out what it is cos its so crammed.

dude, thats shit, they're look for the person that can answer the question.

As for me, i just used another writing booklet, there was no way i could do fermentation, distillation and estrification in one page.

 

[stef.]

dude, thats shit, they're look for the person that can answer the question.

As for me, i just used another writing booklet, there was no way i could do fermentation, distillation and estrification in one page.

ur right..but compare someone who can write all that in one page to someone who took a page and a booklet to write all that? nb: no waffling means answering the question

but if u can write that much ..then go u... =]

 

[richz]

Thats what I got, i think its right... 0.052% or something looking like that maybe?

cool bananas

anyway do u purifiy ethanol by distillation, if it is, wohoo, i took a stab at that

 

[Mr_Olympia]

Very Easy

Very Very Easy.......... The calculations were dead easy and the formulas were also easy

I took the exam home and went over my answers minimun ill get is 95 CHERRING !!

 

[stef.]

anyway do u purifiy ethanol by distillation

i think so..tahts what i would do..distill it several times to obtain pure ethanol..i think

 

[queenie]

there was so much involved in that question though,
i mean after the distillation (xrtzx, yea, thats how u purify ethanol), you had to weigh the ethanol produced so you could get the same amount of butanonic acid, then carry out estrification (remembering the hs2o4 and the boiling chips... blah blah blah), then add NaHco3 to remove excess butanoic acid and h2so4, then separating funnel, then fractioanal distiallation to remove ester at boiling point...

 

[laserbrainz]

that 7 marker - ended up using the page with a 6 line diagram, but used 2 more lines on base of page. My writing is tiny though (15-20 words/line) so that made it a full page

 

[stef.]

u have to weigh it the ethanol??

i thought u would add in excess (well the more denser one that is) so that it would increase yield by Mr. Le Chatlier??

confusion

 

[queenie]

could do i suppose...

but arn't we told in estrification to add the same volume of alochol and alcaonic acid?