Predictions for Chemistry 2014 HSC? (1 Viewer)

[SuchSmallHands]

Oh and the maintenance of correct stoichiometric ratios of reactants (if that counts as a condition). I also want to add regular catalyst replacement/maintenance but it doesn't seem like a 'condition' per se to me.

 

[SuchSmallHands]

This question was 2003, so before the days of sample answers, but I found the marking criteria if anyone's interested.

MARKING GUIDELINES

6–7
• Demonstrates an extensive knowledge of the Haber process including
factors that are monitored and managed.
• Provides a comprehensive explanation of why reaction conditions are
monitored or managed, relating these to the nature of the reaction
• Provides an evaluation

4–5
• Demonstrates a thorough knowledge of the Haber process
• Explains why some reaction conditions are monitored or managed

2-3
• Demonstrates a sound knowledge of the Haber process
OR
• Demonstrates a limited knowledge of the Haber process and identifies a
reaction condition(s) that is (2 marks)/are monitored or managed (3 marks)

1
• Identifies the reactants and product of the Haber process
OR
• Gives one correct statement about the Haber process
OR
• Identifies one reaction condition that is monitored

 

[faisalabdul16]

Also need to use gas liquid chromatography to ensure no carbon monoxide or sulfur poisons the catalyst.

 

[SuchSmallHands]

Also need to use gas liquid chromatography to ensure no carbon monoxide or sulfur poisons the catalyst.

Yeah I'd probably only give myself around a four for that answer to be honest.

Outline one method to monitor stratospheric ozone (2)

 

[QZP]

Is there a difference between manage vs monitor they want usto pick on? :S

 

[SuchSmallHands]

Yeah, I think they want us to talk about instruments (total ozone mapping spectrometer, dobson ozone spectrometer, etc) instead of what we do to manage ozone depletion?

 

[SuchSmallHands]

For example, I'd write something like this:

The Dobson ozone spectrometer is a ground based instrument for determining stratospheric ozone concentration. It records the intensity of a single wavelength of UVA light (315-400nm wavelengths) and one wavelength of UVB light (315-280nm wavelengths). As only wavelengths <310nm can photolysise O3, UVA light can pass through the ozone layer unaffected, thus the intensity of the UVA light acts as a reference point against which UVB light intensity can be assessed and O3 concentration extrapolated.

 

[SuchSmallHands]

*stratospheric O3 concentration, that is.

 

[faisalabdul16]

TOMS -
These instruments have been on board several US satellites such as the Nimbus 7 over the past 20 years. They make 14 polar orbits per day measuring the frequency of light scattered back into the space from the earths surface. They can scan through the atmosphere and measure ozone concentration as a function of altitude and geographic position. Ozone profiles and contour maps can be formed to measure ozone concentrations at different parts and surfaces of the world. The accuracy of TOMS has been within 3-4% of actual ozone concentrations.

 

[photastic]

TOMS -
These instruments have been on board several US satellites such as the Nimbus 7 over the past 20 years. They make 14 polar orbits per day measuring the frequency of light scattered back into the space from the earths surface. They can scan through the atmosphere and measure ozone concentration as a function of altitude and geographic position. Ozone profiles and contour maps can be formed to measure ozone concentrations at different parts and surfaces of the world. The accuracy of TOMS has been within 3-4% of actual ozone concentrations.

Assess the safety of growing crops near rivers.

 

[faisalabdul16]

Not safe. Eutrophication lel

haha i got sick of doing eutrophication questions

Name and explain how one recently discovered transuranic element is formed. 2 marks

 

[SuchSmallHands]

Not safe. Eutrophication lel

haha i got sick of doing eutrophication questions

Name and explain how one recently discovered transuranic element is formed. 2 marks

(If we could all just ignore the fact that I'm doing chem questions on BOS at 12:45am that'd be great)

Copernicum (first produced 1996) is formed by accelerating Zn70 nuclei at a Pb208 nucleus in a heavy ion accelerator: 208/82Pb + 70/30Zn ---> 1/0 n + 277/112 Cn

 

[faisalabdul16]

(If we could all just ignore the fact that I'm doing chem questions on BOS at 12:45am that'd be great)

Copernicum (first produced 1996) is formed by accelerating Zn70 nuclei at a Pb208 nucleus in a heavy ion accelerator: 208/82Pb + 70/30Zn ---> 1/0 n + 277/112 Cn

Dw im also up HAHAH
Interesting, never heard of that.
Darmstadatidium is produced by the bombardment of lead-208 with nickel-64

Explain how a buffer works and its importance in a natural system. 3 marks

 

[seventhroot]

Dw im also up HAHAH
Interesting, never heard of that.
Darmstadatidium is produced by the bombardment of lead-208 with nickel-64

Explain how a buffer works and its importance in a natural system. 3 marks

I'll have a go

A buffer (according to wiki) is something used to maintain the pH of a system and maintaining the pH of a natural system is important

state rank right here

 

[Queenroot]

I'll have a go

A buffer (according to wiki) is something used to maintain the pH of a system and maintaining the pH of a natural system is important

state rank right here

would give 1/3

 

[faisalabdul16]

would give 1/3

I would give it 0.5/3 but because in hsc no half marks, it is a 0. You got a pessimistic marker, he doesn't see it as being rounded to 1 but instead 0

 

[seventhroot]

would give 1/3

Would still take that mark


how about this:

Buffers are solutions that minimize changes in concentrations of H or OH ions. < Something on Le Chatelier's Principle >.

relevant video:

 

[Queenroot]

You tried

 

[seventhroot]

You tried

an attempt was made.jpg

I'll post the next question cos I rekt the last one

explain how the use of a catalyst lowers the reaction temperature required, in your answer; also identify the catalyst(s) used in the Haber process (4 marks)

 

[faisalabdul16]

an attempt was made.jpg

I'll post the next question cos I rekt the last one

explain how the use of a catalyst lowers the reaction temperature required, in your answer; also identify the catalyst(s) used in the Haber process (4 marks)

We did a Haber question earlier