HSC 2012-2015 Chemistry Marathon (archive) (2 Viewers)

[BlueGas]

re: HSC Chemistry Marathon Archive

If the exam has that question I'll buy ekman a car.

From the 1990s.

 

[Ekman]

re: HSC Chemistry Marathon Archive

If the exam has that question I'll buy ekman a car.

Ooo and if the hsc doesn't have that question then you don't buy me a car... you buy me a house

Deal?

 

[Gabriel Moussa]

re: HSC Chemistry Marathon Archive

Although the dot point says to have one specific chemist, meaning you have to find an actual chemist who has to be working. I have heard that you need one male and one female chemist who have different roles.

In terms of the chemical principles, you can say AAS I guess. It got more to do with what kind of knowledge the chemist has when solving an issue. For example: knowledge of acid and base reactions in order to neutralise spills

It doesn't actually asked for a named chemist it asks for a named enterprise, so simply stating an environmental chemist working for the EPA/ an analytical chemist working for a blood doping agency would be sufficient.

For that stupid named male chemist I would just use Alan Walsh since we already know him --> CSIRO --> Development of AAS --> significance

 

[Mr_Kap]

re: HSC Chemistry Marathon Archive

It doesn't actually asked for a named chemist it asks for a named enterprise, so simply stating an environmental chemist working for the EPA/ an analytical chemist working for a blood doping agency would be sufficient.

For that stupid named male chemist I would just use Alan Walsh since we already know him --> CSIRO --> Development of AAS --> significance

So is alan walsh an analytical chemist?

 

[BlueGas]

re: HSC Chemistry Marathon Archive

Get copper strips/copper shackles and in a fume cabinet put dilute sulfuric acid on it and watch the solution turn blue. Gloves and shiiettt.

Do the same for sucrose or ethanol

How about the results for dehydration of ethanol? I know the products are ethene and water but how are they actually observed?

 

[Drsoccerball]

re: HSC Chemistry Marathon Archive

How about the results for dehydration of ethanol? I know the products are ethene and water but how are they actually observed?

Okay i guess sucrose would be better When it undergoes dehydration it turns black.

 

[BlueGas]

re: HSC Chemistry Marathon Archive

Okay i guess sucrose would be better When it undergoes dehydration it turns black.

Wow lol.

Okay so there's this question in 2010 HSC paper for Industrial asking to compare the electrolysis methods molten NaCl and aqueous NaCl. Since aqueous can be both concentrated and dilute, the question didn't specifiy which, and in the sample answers, they mentioned the reactions for concentrated, did they do this on purpose or you can put the reactions for conc. or dilute?

 

[Ekman]

re: HSC Chemistry Marathon Archive

Wow lol.

Okay so there's this question in 2010 HSC paper for Industrial asking to compare the electrolysis methods molten NaCl and aqueous NaCl. Since aqueous can be both concentrated and dilute, the question didn't specifiy which, and in the sample answers, they mentioned the reactions for concentrated, did they do this on purpose or you can put the reactions for conc. or dilute?

I would talk about both concentrated and dilute aqueous solutions. Its a 5 marker so I guess 3 marks for all three types of electrolysis and the final 2 on equations and the final comparison

 

[Ekman]

re: HSC Chemistry Marathon Archive

Okay i guess sucrose would be better When it undergoes dehydration it turns black.

It doesn't just go black, it forms a carbon snake.

 

[leehuan]

re: HSC Chemistry Marathon Archive

It doesn't actually asked for a named chemist it asks for a named enterprise, so simply stating an environmental chemist working for the EPA/ an analytical chemist working for a blood doping agency would be sufficient.

For that stupid named male chemist I would just use Alan Walsh since we already know him --> CSIRO --> Development of AAS --> significance

I don't know about this.

 

[BlueGas]

re: HSC Chemistry Marathon Archive

I would talk about both concentrated and dilute aqueous solutions. Its a 5 marker so I guess 3 marks for all three types of electrolysis and the final 2 on equations and the final comparison

There's something weird about the sample answer though, it says in both cells Cl- ions are eventually oxidised, but dilute NaCl doesn't have any Cl- ions in the equations, Cl- ions are only present in concentrated and molten. What sort of aqueous NaCl are they talking about?

 

[leehuan]

re: HSC Chemistry Marathon Archive

Wow lol.

Okay so there's this question in 2010 HSC paper for Industrial asking to compare the electrolysis methods molten NaCl and aqueous NaCl. Since aqueous can be both concentrated and dilute, the question didn't specifiy which, and in the sample answers, they mentioned the reactions for concentrated, did they do this on purpose or you can put the reactions for conc. or dilute?

This can be a trap. My physics teacher stressed this absolutely. Sometimes the sample answers are a random grab bag. They might not necessarily be a band 6 answer.

I always consult the marking criteria and excel success one.

 

[leehuan]

re: HSC Chemistry Marathon Archive

There's something weird about the sample answer though, it says in both cells Cl- ions are eventually oxidised, but dilute NaCl doesn't have any Cl- ions in the equations, Cl- ions are only present in concentrated and molten. What sort of aqueous NaCl are they talking about?

Concentrated. Because you're right, electrolysis of dilute NaCl is basically electrolysis of H2O.

EDIT: Unless they mean this
After a ton of the H2O has been oxidised, the concentration of H2O and the concentration of Cl(-) become about equal. At this point, oxidation of both occurs, given you still have enough reactant.

 

[BlueGas]

re: HSC Chemistry Marathon Archive

This can be a trap. My physics teacher stressed this absolutely. Sometimes the sample answers are a random grab bag. They might not necessarily be a band 6 answer.

I always consult the marking criteria and excel success one.

So the sample answers are actually wrong when they say in both cells Cl- ions are oxidised? I don't know how this is possible anyway so this is not the case for dilute.

 

[leehuan]

re: HSC Chemistry Marathon Archive

So the sample answers are actually wrong when they say in both cells Cl- ions are oxidised? I don't know how this is possible anyway so this is not the case for dilute.

I reckon they are wrong. But read my edited post above.

 

[rand_althor]

re: HSC Chemistry Marathon Archive

I'm sure there isn't going to be a question asking you: Name one "female" scientist...

Its in the syllabus, so its a possibility I think. You are required to "gather information from secondary sources by identifying practising male and female Australian scientists, the areas in which they are currently working and information about their research" (Outcome H12, 12.3e, page 44 - Chemistry syllabus).

 

[BlueGas]

re: HSC Chemistry Marathon Archive

I just came across this question and I have no idea how to answer this, I didn't do the case study for arsenic so how am I meant to answer this?

 

[Drsoccerball]

re: HSC Chemistry Marathon Archive

I just came across this question and I have no idea how to answer this, I didn't do the case study for arsenic so how am I meant to answer this?

Is it a trial question...? Or a HSC question ? Regardless i would make up BS.

 

[porcupinetree]

re: HSC Chemistry Marathon Archive

I just came across this question and I have no idea how to answer this, I didn't do the case study for arsenic so how am I meant to answer this?

I have absolutely no idea what I'd write

 

[BlueGas]

re: HSC Chemistry Marathon Archive

Is it a trial question...? Or a HSC question ? Regardless i would make up BS.

It's a trial question.

But I need help for this question, the sample answer still doesn't make me understand why cell Y was chosen.