Predictions for Chemistry 2014 HSC? (5 Viewers)

[emilios]

Last question from me for the time being:

Is this D? Since the 2nd reaction isnt reversible then the amount of SO2 is unchanged. However, SO4-2 is the conjugate base of sulfuric acid and hence adding base to the solution would decrease acidity (by like the tiniest amount tho lol)

Is that right?

 

[faisalabdul16]

Is this D? Since the 2nd reaction isnt reversible then the amount of SO2 is unchanged. However, SO4-2 is the conjugate base of sulfuric acid and hence adding base to the solution would decrease acidity (by like the tiniest amount tho lol)

Is that right?

I said C because the addition of a solid to an equilibrium has no effect, automatically ruling out A and B. And then sodium sulfate is a neutral salt, therefore its addition will have no pH change.

 

[Queenroot]

Both of you are wrong

 

[Queenroot]

K den I was hoping you guys would react

Faisal you're correct

 

[faisalabdul16]

K den I was hoping you guys would react

Faisal you're correct

haha
need to get band 6.

 

[emilios]

I said C because the addition of a solid to an equilibrium has no effect, automatically ruling out A and B. And then sodium sulfate is a neutral salt, therefore its addition will have no pH change.

Oh right the only part I was confused with was whether sodium sulfate was a basic or neutral salt. Need to revise that part.

 

[Speed6]

Guys for that question the answer is C

 

[faisalabdul16]

Oh right the only part I was confused with was whether sodium sulfate was a basic or neutral salt. Need to revise that part.

I know this easy trick to apply but hard to explain.

 

[emilios]

I know this easy trick to apply but hard to explain.

Work back from what reaction it was produced? E.g. in this case it's produced from sulfuric acid and sodium hydroxide, forming a neutral salt (strong+strong--> neutral). Is that what you were heading towards or was it something else?

 

[faisalabdul16]

Work back from what reaction it was produced? E.g. in this case it's produced from sulfuric acid and sodium hydroxide, forming a neutral salt (strong+strong--> neutral). Is that what you were heading towards or was it something else?

Spot on! That's exactly what i do, hence no need for revision.

haha good explanation, i use analogies such as pretending the salt is the child and what are the parents blah blah hahahaha

 

[Speed6]

Question

 

[faisalabdul16]

Question

A

Give wordy questions!

 

[Queenroot]

A

Give wordy questions!

ikr he's giving MC too easy

 

[faisalabdul16]

ikr he's giving MC too easy

Why did you stop giving questions?

 

[Queenroot]

Why did you stop giving questions?

Cos the twelvie rekt the business

Anyway, explain ozone depletion with equations

 

[Speed6]

Alright guys I'll see what I can find

 

[Speed6]

 

[seventhroot]

you could just go here: http://www4.boardofstudies.nsw.edu.au/course/higher-school-certificate/chemistry/

 

[faisalabdul16]

Cos the twelvie rekt the business

Anyway, explain ozone depletion with equations

Ozone depletion occurs because of chlorofluorocarbons. Chlorofluorocarbons are alkane molecules with the hydrogens replaced with chlorine or fluorine molecules. In the troposphere these chemicals are extremely stable, chemically inert and unreactive. They are non-corrosive chemicals which were originally used to replace ammonia as refrigerants and in air conditioners. When chlorofluorocarbons leak into the atmosphere they travel up to the stratosphere and cause ozone depletion as strong uv Rays split the molecule forming free radicals.

CClF2 + UV ----> Cl(radical) + CF2 (radical)
Cl + O3 ---> ClO (radical) + O2
ClO radical + oxygen radical ---> Cl radical plus oxygen

As apparent, chlorofluorocarbons cause ozone depletion and during the process the chlorine radical is regenerated and known as a catalyst. One chlorine radical can destroy thousands of ozone molecules before being removed by methane

 

[Queenroot]

Ozone depletion occurs because of chlorofluorocarbons. Chlorofluorocarbons are alkane molecules with the hydrogens replaced with chlorine or fluorine molecules. In the troposphere these chemicals are extremely stable, chemically inert and unreactive. They are non-corrosive chemicals which were originally used to replace ammonia as refrigerants and in air conditioners. When chlorofluorocarbons leak into the atmosphere they travel up to the stratosphere and cause ozone depletion as strong uv Rays split the molecule forming free radicals.

CClF2 + UV ----> Cl(radical) + CF2 (radical)
Cl + O3 ---> ClO (radical) + O2
ClO radical + oxygen radical ---> Cl radical plus oxygen

As apparent, chlorofluorocarbons cause ozone depletion and during the process the chlorine radical is regenerated and known as a catalyst. One chlorine radical can destroy thousands of ozone molecules before being removed by methane

Cut down on why CFC's are used, unnecessary. You didn't define what Ozone depletion is. I would give it 4/6.