2003 HSC Industrial Chem Help (1 Viewer)

[ben7]

Hi, was wondering if anyone had solutions for the 2003 HSC industrial chem section and could help me out in thes 3 Qs, i have a abit of an idea how to answer the two long ones but havnt really got anything to compare my answers too.

Just an outline for an answer for Q30(c), (d)iii and (e) would be great and helpful to other people as well. ill put the Qs up.

Q30 (c): Analyse how an understanding of the structure and cleaning action of soaps led to the development of synthetic detergents. 5 Marks

Q30 (e): Asses how the environmental issues have been addressed in an industrial method of production of an acid, and an industrial method of production of a base. 6 Marks

There we go.
Thanks alot.

Ben

 

[ben7]

Answer written kindly by ashtor to (c):
They found out that the cleaning action of soaps was seriously hindered by hard water due to scum formation...so synthetics that were much better in hard water were developed. However, due to their branched chain structure they weren't biodegradable and so formed foam in rivers etc..So furhter reserach made straighter chain anionics that could be broken down by bacteria into CO2 and H2O. Further reserach led to the development of cationics and anionics for different purposes and these wre completely unaffeceted by hard water (unlike anionics that tied up), but cationics were found to have biocidal properties.

 

[wahashtini]

for the acid part- u talk bout the industrial production of sulfuric acid, and then u talk bout the environmental part: How sulfur rreacts wit oxygen forming oxides of sulfur which is a lower atmosphere pollutant, also leads to formation of acid rain.
Also the superheated water, may have other impurities, which is bad when its discharged into waterways.
(if there's more plz tell me)

for base u talk bout either solvay process-production of sodium carbonate, which is tooo long to type all thepoints but in general, the disposal of CaCl2, How ammonia can leak from old plants, and the heat produced since solvay process is exothermic,

Or u can talk bout production of NaOH- diagpragm, membrane or mecury cell, and their environmental problems.

 

[ben7]

Thanks alot. Yeh i didnt think to relate the Frasch process with the formation of acid rain yeah it all makes sense now.

Another problem with that sulfur extraction is subsidence which is the earth collapsing over the mine.

Ben

 

[wahashtini]

"Another problem with that sulfur extraction is subsidence which is the earth collapsing over the mine."

thanxx for that one, cause i haven't heard it b4, but thanku

 

[ben7]

When u say the process to produce sulfuric acid are u refering to the contact process or the frasch process or can we write about both do u know?

another Q are the equns relating to the polution:

S(s) + O2(g) -> SO2(g) oxidation of S
and
S(s) + H2(g) -> H2S(g) reduction of S

i have the names of pollutants in my notes but didnt have how they formed.

thanks
Ben

 

[beta-omega]

production of sulfuric acid is the contact process, the frasch process is the extraction of sulfur... some difference... yeah, i'd be safe and put both

 

[KungPow]

I don't think you'd be talking about the Frasch method since it only asks for industrial production of acid and not extraction of sulfur

 

[ben7]

I don't think you'd be talking about the Frasch method since it only asks for industrial production of acid and not extraction of sulfur

well wat are the environmental issues with the Contact process then. i dont remember learning any, is it in the syllabus? i remember with conact is similar to haber process and need to be monitered and controlled like haber process but not environmental stuff mmm, might need to look into that.

 

[KungPow]

Well according to the syllabus:

<i>describe the processes used to extract sulphur from mineral deposits, identifying the
properties of sulphur which allow its extraction and analysing potential environmental
issues that may be associated with its extraction</i>

There's no mention of environmental issues for the production of sulfuric acid I think so maybe that was just a bad question?

 

[sub]

Well according to the syllabus:

<i>describe the processes used to extract sulphur from mineral deposits, identifying the
properties of sulphur which allow its extraction and analysing potential environmental
issues that may be associated with its extraction</i>

There's no mention of environmental issues for the production of sulfuric acid I think so maybe that was just a bad question?

its not necessarily a bad q...cos the production of h2so4 is not perfect, some so2 escapes into the air...i think if u look at conq chem, the process they use is 99.7% efficient, while 0.3% of so2 escapes into the air. (this is because the equilibrium of so2 <=> so3 is not 100% complete). this then allows for the formation of h2so4. note: this process uses 3 contact beds (the first at 550°, the next 2 at 400°). the 0.3% os so2 released is ok according to govt standards... but it still forms acid rain.
i hope that helps...refer to conq chem for more stuff...and if u dont have it...well try to pm me, and ill get back to u if im on.

GL ppl