Question from 2009 HSC (1 Viewer)

[roryclifford]

Hi Guys and Gals,

I am wondering which dotpoint in the Syllabus this question from the 2009 HSC actually refers to and how you would suggest answering this. The sample HSC answers are 1 and a half typed pages for a 5 marker, which is obviously in great excess to what should have been required.

"The has been an increase in the concentration of oxides of Nitrogen in the atmosphere as a result of combustion. Assess both the evidence to the support this statement and the need to monitor these oxides" 5 Marks

Now, when doing this I mentioned the increase in use of motor vehicles, the destruction of Ozone which is caused by NO and also the creation in the Troposphere by NO2, but this was not mentioned in the answer.

Thanks

 

[muzeikchun852]

I think there is a dot point on this and I'm not too sure but I don't think effect is included.

 

[s2 SEductive]

From my success one book!
=]

Oxides of nitrogen are produced mainly from internal combustion engines and coal burning power stations:
N2(g) + O2(g) --> 2NO(g)
2NO(g) + O2 --> 2NO2(g)

The conc. of these oxides have increased with the rapid increase in car numbers in the world since about 1945.The evidence for this increase comes from both direct measurements of gas conc. in the atmosphere and indirectly through increases in level of photochemical smog in cities and increased levels of acid rain. The quantitative measurements are accurate and reliable but the technology has only been available in recent times. The smog and acid rain evidence is less reliable as they could be formed by other oxides and other factors may have led to their increase.

The need to monitor: countinued monitoring of [NO] in the atmosphere is vitally important as only when we record increasing levels of pollution will we act to reduce it. It is important to reduce levels of NOx as it has a direct negative effect on the population's health, as it can cuase respiratory diseases. It also affects the surrounding environment, as acid rain can strip the cuticle off leaves leading to degradation of forests.

2NO2 + H2O --> HNO2+HNO3
----------------------------------------------------------------------------------

 

[kfnmpah]

From my success one book!
=]

Oxides of nitrogen are produced mainly from internal combustion engines and coal burning power stations:
N2(g) + O2(g) --> 2NO(g)
2NO(g) + O2 --> 2NO2(g)

The conc. of these oxides have increased with the rapid increase in car numbers in the world since about 1945.The evidence for this increase comes from both direct measurements of gas conc. in the atmosphere and indirectly through increases in level of photochemical smog in cities and increased levels of acid rain. The quantitative measurements are accurate and reliable but the technology has only been available in recent times. The smog and acid rain evidence is less reliable as they could be formed by other oxides and other factors may have led to their increase.

The need to monitor: countinued monitoring of [NO] in the atmosphere is vitally important as only when we record increasing levels of pollution will we act to reduce it. It is important to reduce levels of NOx as it has a direct negative effect on the population's health, as it can cuase respiratory diseases. It also affects the surrounding environment, as acid rain can strip the cuticle off leaves leading to degradation of forests.

2NO2 + H2O --> HNO2+HNO3
----------------------------------------------------------------------------------

This takes me back. That's pretty much exactly what I wrote in my exam haha.
I'm sure your teacher would have told you this, but always include equations in written responses.
Always.

 

[s2 SEductive]

This takes me back. That's pretty much exactly what I wrote in my exam haha.
I'm sure your teacher would have told you this, but always include equations in written responses.
Always.

Yup =]=]

 

[roryclifford]

From my success one book!
=]

Oxides of nitrogen are produced mainly from internal combustion engines and coal burning power stations:
N2(g) + O2(g) --> 2NO(g)
2NO(g) + O2 --> 2NO2(g)

The conc. of these oxides have increased with the rapid increase in car numbers in the world since about 1945.The evidence for this increase comes from both direct measurements of gas conc. in the atmosphere and indirectly through increases in level of photochemical smog in cities and increased levels of acid rain. The quantitative measurements are accurate and reliable but the technology has only been available in recent times. The smog and acid rain evidence is less reliable as they could be formed by other oxides and other factors may have led to their increase.

The need to monitor: countinued monitoring of [NO] in the atmosphere is vitally important as only when we record increasing levels of pollution will we act to reduce it. It is important to reduce levels of NOx as it has a direct negative effect on the population's health, as it can cuase respiratory diseases. It also affects the surrounding environment, as acid rain can strip the cuticle off leaves leading to degradation of forests.

2NO2 + H2O --> HNO2+HNO3
----------------------------------------------------------------------------------

Oh champion! Exactly what I needed, cheers!