Predictions for Chemistry 2014 HSC? (1 Viewer)

[SuchSmallHands]

Is it in the syllabus?

Someone check?

No, there's no direct mention of it.

 

[QZP]

I remember learning it in year 11 but not sure if they can test on that

 

[SuchSmallHands]

I remember learning it in year 11 but not sure if they can test on that

I do remember my teacher talking about the catalytic converters and scrubbers really briefly this year when we did that oxides of nitrogen and sulfur/acid rain context statement. But looking at the syllabus I don't see how they could directly test us on it.

 

[GOsie]

If you need a break, try: Explain the formation and effects of acid rain (5 marks).

Acid rain is mostly formed from the acidic oxides SO2 and NO2.
SO2 is formed naturally from volcanic eruptions and is formed industrially during the combustion of many fossil fuels.
Sulfur dioxide reacts with water to form sulfurous acid, which reacts with oxygen to form sulfuric acid
SO2g + H2O(L) -> H2SO3(aq)
2H2SO3(aq) + O2g -> 2H2SO4(aq)
Sufuric acid dissociates in water to to form a hydronium ion, giving the rain its acidic properties.
H2SO4(aq) + H2O(L) -> H3O(aq)+ + HSO4-(aq)


NO2 is formed industrially during the combustion of fossil fuels in internal combustion engines in cars, and is also formed naturally in the atmosphere by a series of reactions.

N2 and O2 react in the high temperature of lightning.
N2g + O2g -> 2NOg
2NOg + O2g -> 2NO2g
Nitrogen dioxide reacts with water to form nitric acid
NO2g +H2O -> H2NO3(aq)
and nitric acid dissociates in water to form a hydronium ion, which gives it its acidic properties
H2NO3(aq) + H2O -> H3O+ + HNO3-(aq)


Acid rain has significant detrimental effects on the natural environment, and the built environment:

Acid rain can kill marine life, as aquatic environments tend to flourish in a small pH range, thus as strong acids are introduced (H2SO4 or H2NO3), the pH of water lowers (becomes more acidic) and can severely damage the water body, killing most living organisms within it.
It can also destroy crops and render the farmland unusable (many crops cannot grow in acidic soils).
They also can cause lung problems for humans if particles are inhaled.

Acid rain also damages buildings, car paints and statues, particularly those made of sandstone. This has both a visual and monetary cost.


Did I miss anything important?

 

[enigma_1]

Acid rain is mostly formed from the acidic oxides SO2 and NO2.
SO2 is formed naturally from volcanic eruptions and is formed industrially during the combustion of many fossil fuels.
Sulfur dioxide reacts with water to form sulfurous acid, which reacts with oxygen to form sulfuric acid
SO2g + H2O(L) -> H2SO3(aq)
2H2SO3(aq) + O2g -> 2H2SO4(aq)
Sufuric acid dissociates in water to to form a hydronium ion, giving the rain its acidic properties.
H2SO4(aq) + H2O(L) -> H3O(aq)+ + HSO4-(aq)


NO2 is formed industrially during the combustion of fossil fuels in internal combustion engines in cars, and is also formed naturally in the atmosphere by a series of reactions.

N2 and O2 react in the high temperature of lightning.
N2g + O2g -> 2NOg
2NOg + O2g -> 2NO2g
Nitrogen dioxide reacts with water to form nitric acid
NO2g +H2O -> H2NO3(aq)
and nitric acid dissociates in water to form a hydronium ion, which gives it its acidic properties
H2NO3(aq) + H2O -> H3O+ + HNO3-(aq)


Acid rain has significant detrimental effects on the natural environment, and the built environment:

Acid rain can kill marine life, as aquatic environments tend to flourish in a small pH range, thus as strong acids are introduced (H2SO4 or H2NO3), the pH of water lowers (becomes more acidic) and can severely damage the water body, killing most living organisms within it.
It can also destroy crops and render the farmland unusable (many crops cannot grow in acidic soils).
They also can cause lung problems for humans if particles are inhaled.

Acid rain also damages buildings, car paints and statues, particularly those made of sandstone. This has both a visual and monetary cost.


Did I miss anything important?

yeah good 4/5

but would have liked something more on the effects, eg this is copied from my post a while ago:

"Formation of acid rain which can destroy entire forests, corrode limestone structures:
CaCo3(s) + H2SO4(aq) --> CaSO4(aq) + CO2(g) + H20(l) where the CaSO4 is soluble and is washed away.
And also, acid rain corroding metal structures:
H2S04(aq) + Fe(s) -->FeSO4(aq) + H2(g)
Acid rain also distorts the pH levels in water bodies."

Something with equations looks pretty and no marker will take off any marks

 

[GOsie]

For my question (Shipwrecks if any of you do it):

i) Name of method for removing salt from an artifact recovered from a wreck (1 mark)
ii) Explain, with reference to two examples, chemical procedures used to clean and preserve artifacts from wrecks (5 marks)


For those who don't do Shipwrecks:

Assess the suitability of biomass as a future source of energy and chemicals for industry (5 marks)

 

[GOsie]

yeah good 4/5

but would have liked something more on the effects, eg this is copied from my post a while ago:

"Formation of acid rain which can destroy entire forests, corrode limestone structures:
CaCo3(s) + H2SO4(aq) --> CaSO4(aq) + CO2(g) + H20(l) where the CaSO4 is soluble and is washed away.
And also, acid rain corroding metal structures:
H2S04(aq) + Fe(s) -->FeSO4(aq) + H2(g)
Acid rain also distorts the pH levels in water bodies."

Something with equations looks pretty and no marker will take off any marks

Thanks I meant limestone not sandstone!

 

[enigma_1]

For my question (Shipwrecks if any of you do it):

i) Name of method for removing salt from an artifact recovered from a wreck (1 mark)
ii) Explain, with reference to two examples, chemical procedures used to clean and preserve artifacts from wrecks (5 marks)


For those who don't do Shipwrecks:

Assess the suitability of biomass as a future source of energy and chemicals for industry (5 marks)

aww yisss shipwrecks buddy ))

Someone give an answer ))

Thanks I meant limestone not sandstone!

ahah all good!

 

[SuchSmallHands]

All these people with their mainstream option topics... #barrierstobelonging

 

[faisalabdul16]

No, there's no direct mention of it.

So we wont be directly asked

 

[SuchSmallHands]

So we wont be directly asked

Nope, just good to know if the question allows you to talk about it (and I don't think that many would). I don't think it's worth remembering the reactions or anything.

 

[faisalabdul16]

Nope, just good to know if the question allows you to talk about it (and I don't think that many would). I don't think it's worth remembering the reactions or anything.

thank you

 

[seventhroot]

meanwhile in the physics predictions thread

 

[SuchSmallHands]

meanwhile in the physics predictions thread

I learned from the scientist study involved in my one term of physics that physicists invariably fight like 12 year old girls. A thread of all of them together was never going to work out.

 

[faisalabdul16]

More questions? Some of us can do while on english break lel

 

[GOsie]

More questions? Some of us can do while on english break lel

I've posted two unanswered questions here.

For my question (Shipwrecks if any of you do it):

i) Name of method for removing salt from an artifact recovered from a wreck (1 mark)
ii) Explain, with reference to two examples, chemical procedures used to clean and preserve artifacts from wrecks (5 marks)


For those who don't do Shipwrecks:

Assess the suitability of biomass as a future source of energy and chemicals for industry (5 marks)

 

[faisalabdul16]

I've posted two unanswered questions here.

Biomass is carbon-based material produced by living organisms, mainly plants however the term also includes animal excreta. The major component of biomass is cellulose, from which ethanol can be formed. Cellulose has 6 carbon atoms joined together so that it can be regarded as the basic structure for starting chemicals for the petrochemical industry. Ethanol from Cellulose - Cellulose is extracted from plants such as sugar cane or corn, and are digested in strong aqueous sulfuric acid (4M) to breakdown the cellulose into glucose. The insoluble matter, particularly ligin from wood pulp is removed along with other impurities through fractional distillation. The solution is then neutralised to remove the acid, and a pure solution of glucose is formed. Glucose then undergoes a process called fermentation. Fermentation is the process by which ethanol and carbon dioxide is produced by yeast, in the absence of air (anaerobic respiration) and at 35 degrees celsius from glucose. The ethanol extracted can then be dehydrated to form ethylene, an important monomer used in the industry for the production of plastic and soap, or the ethanol can remain in it's state and be used as fuel or as a solvent. The advantages of ethanol as a fuel are that it is renewable, made from plants. The oxygen in the ethanol molecule means that its combustion will always be complete, and no toxins such as Carbon monoxide will be produced. And also has a higher flash point then petrol, meaning it's safer to store in humid conditions. However, there are some disadvantages concerned - large areas of arable land need to be devoted to the cultivation of plants such as sugar and corn, ethanol has a lower heat of combustion, therefore one would have to fill up more often and fermentation creates a lot of waste products.

Evaluation - Despite the negatives associated with the use of biomass as a future source of energy and chemicals for industry, the advantages outweigh the negatives as the world's petroleum supplies are expected to run out in 70 years and thus alternative methods need to be formed. Biomass will only be a suitable and reliable source of energy and chemicals, if the production of chemicals such as ethanol are done in an efficient and cost effective manner. Current production methods are too time consuming and very costly.

This is beyond the info required for 5 marks, just showing how there is a scope of things you can talk about. Also there is one equation in there (dehydration of ethanol) but ceebs putting it.

 

[enigma_1]

Biomass is carbon-based material produced by living organisms, mainly plants however the term also includes animal excreta. The major component of biomass is cellulose, from which ethanol can be formed. Cellulose has 6 carbon atoms joined together so that it can be regarded as the basic structure for starting chemicals for the petrochemical industry. Ethanol from Cellulose - Cellulose is extracted from plants such as sugar cane or corn, and are digested in strong aqueous sulfuric acid (4M) to breakdown the cellulose into glucose. The insoluble matter, particularly ligin from wood pulp is removed along with other impurities through fractional distillation. The solution is then neutralised to remove the acid, and a pure solution of glucose is formed. Glucose then undergoes a process called fermentation. Fermentation is the process by which ethanol and carbon dioxide is produced by yeast, in the absence of air (anaerobic respiration) and at 35 degrees celsius from glucose. The ethanol extracted can then be dehydrated to form ethylene, an important monomer used in the industry for the production of plastic and soap, or the ethanol can remain in it's state and be used as fuel or as a solvent. The advantages of ethanol as a fuel are that it is renewable, made from plants. The oxygen in the ethanol molecule means that its combustion will always be complete, and no toxins such as Carbon monoxide will be produced. And also has a higher flash point then petrol, meaning it's safer to store in humid conditions. However, there are some disadvantages concerned - large areas of arable land need to be devoted to the cultivation of plants such as sugar and corn, ethanol has a lower heat of combustion, therefore one would have to fill up more often and fermentation creates a lot of waste products.

Evaluation - Despite the negatives associated with the use of biomass as a future source of energy and chemicals for industry, the advantages outweigh the negatives as the world's petroleum supplies are expected to run out in 70 years and thus alternative methods need to be formed. Biomass will only be a suitable and reliable source of energy and chemicals, if the production of chemicals such as ethanol are done in an efficient and cost effective manner. Current production methods are too time consuming and very costly.

This is beyond the info required for 5 marks, just showing how there is a scope of things you can talk about. Also there is one equation in there (dehydration of ethanol) but ceebs putting it.

this is godlike.

Every time you post I learn new things, thanks!!

ez 5/5 )

 

[faisalabdul16]

this is godlike.

Every time you post I learn new things, thanks!!

ez 5/5 )

thankyou

We've exhausted every single question.

I can't think of anything that we haven't already asked

 

[GOsie]

Biomass is carbon-based material produced by living organisms, mainly plants however the term also includes animal excreta. The major component of biomass is cellulose, from which ethanol can be formed. Cellulose has 6 carbon atoms joined together so that it can be regarded as the basic structure for starting chemicals for the petrochemical industry. Ethanol from Cellulose - Cellulose is extracted from plants such as sugar cane or corn, and are digested in strong aqueous sulfuric acid (4M) to breakdown the cellulose into glucose. The insoluble matter, particularly ligin from wood pulp is removed along with other impurities through fractional distillation. The solution is then neutralised to remove the acid, and a pure solution of glucose is formed. Glucose then undergoes a process called fermentation. Fermentation is the process by which ethanol and carbon dioxide is produced by yeast, in the absence of air (anaerobic respiration) and at 35 degrees celsius from glucose. The ethanol extracted can then be dehydrated to form ethylene, an important monomer used in the industry for the production of plastic and soap, or the ethanol can remain in it's state and be used as fuel or as a solvent. The advantages of ethanol as a fuel are that it is renewable, made from plants. The oxygen in the ethanol molecule means that its combustion will always be complete, and no toxins such as Carbon monoxide will be produced. And also has a higher flash point then petrol, meaning it's safer to store in humid conditions. However, there are some disadvantages concerned - large areas of arable land need to be devoted to the cultivation of plants such as sugar and corn, ethanol has a lower heat of combustion, therefore one would have to fill up more often and fermentation creates a lot of waste products.

Evaluation - Despite the negatives associated with the use of biomass as a future source of energy and chemicals for industry, the advantages outweigh the negatives as the world's petroleum supplies are expected to run out in 70 years and thus alternative methods need to be formed. Biomass will only be a suitable and reliable source of energy and chemicals, if the production of chemicals such as ethanol are done in an efficient and cost effective manner. Current production methods are too time consuming and very costly.

This is beyond the info required for 5 marks, just showing how there is a scope of things you can talk about. Also there is one equation in there (dehydration of ethanol) but ceebs putting it.

This is pretty amazing! 4.9/5
I would add a little more to the negatives of using it as you only dedicate one sentence about them to the response, which is mostly an analysis of the pros and cons. Doubt it would impact your mark but it's just a suggestion. Well done