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

[someth1ng]

re: HSC Chemistry Marathon Archive

In reality, it's just more scattering of light with HDPE so it looks more opaque.

 

[Drsoccerball]

re: HSC Chemistry Marathon Archive

Can someone help me with the three scientist lavoiser davis and arhenus?

 

[Kaido]

re: HSC Chemistry Marathon Archive

go ahead

 

[Crisium]

re: HSC Chemistry Marathon Archive

Can someone help me with the three scientist lavoiser davis and arhenus?

Lavoisier, Davy and Arrhenius you mean?

 

[Kaido]

re: HSC Chemistry Marathon Archive

it's just rote tbh, like the scientists for 'space' and rocketry

 

[hawkrider]

re: HSC Chemistry Marathon Archive

it's just rote tbh, like the scientists for 'space' and rocketry

tbh, majority of PoM is rote (which is why i hate it barring galvanic cells lol)

but acidic environment is admittedly enjoyable because it relies on understanding

 

[Axio]

re: HSC Chemistry Marathon Archive

tbh, majority of PoM is rote (which is why i hate it barring galvanic cells lol)

but acidic environment is admittedly enjoyable because it relies on understanding

I personally thought that a lot of this topic seemed to be rote except for calculations and a few other exceptions.

 

[hawkrider]

re: HSC Chemistry Marathon Archive

I personally thought that a lot of this topic seemed to be rote except for calculations and a few other exceptions.

eh, even the calculations are repetitive

but no, acidic is the least rote judging from the syllabus. though monitory and management seems like the worst lol

 

[Axio]

re: HSC Chemistry Marathon Archive

eh, even the calculations are repetitive

but no, acidic is the least rote judging from the syllabus. though monitory and management seems like the worst lol

wow ok :/

 

[Fiction]

re: HSC Chemistry Marathon Archive

Can someone help me with the three scientist lavoiser davis and arhenus?

I need help with the flaws in each scientist's theory too c: Any help is much appreciated <333

I understand that Lavoisier (scuse my spelling in advance) 's theory was all about acids having oxygen? Was that just like are generally non-metal oxides are acidic in nature and metal oxides are typically basic? Other than that some non-metal oxides are basic etc, what are some other things does Lavoisier doesn't recognise?

and so on for the rest of the scientists C:

 

[Fiction]

re: HSC Chemistry Marathon Archive

eh, even the calculations are repetitive

but no, acidic is the least rote judging from the syllabus. though monitory and management seems like the worst lol

lol what calculations aren't repetitive? :c

 

[Drsoccerball]

re: HSC Chemistry Marathon Archive

I need help with the flaws in each scientist's theory too c: Any help is much appreciated <333

I understand that Lavoisier (scuse my spelling in advance) 's theory was all about acids having oxygen? Was that just like are generally non-metal oxides are acidic in nature and metal oxides are typically basic? Other than that some non-metal oxides are basic etc, what are some other things does Lavoisier doesn't recognise?

and so on for the rest of the scientists C:

He proposed that all acids have oxygen but this was proven wrong as there can be basic oxides and an acid doesnot have to have oxygen to be an acid..

 

[Fiction]

re: HSC Chemistry Marathon Archive

He proposed that all acids have oxygen but this was proven wrong as there can be basic oxides and an acid doesnot have to have oxygen to be an acid..

Thank you!~
How's Davy's theory of an acid as something which contains replaceable hydrogen, an improvement from Lavoisier's then? C:

 

[Fizzy_Cyst]

re: HSC Chemistry Marathon Archive

Ethanol burns completely in oxygen producing carbon dioxide and water.

Calculate the volume of liquid water formed when the products are condensed at 25degC and 100kPa atmosphere if 91g of ethanol is used in the reaction

 

[zhertec]

re: HSC Chemistry Marathon Archive

C2H5OH (l) + 3O2(g) --> 2CO2(g) + 3H20(g)

91g ethanol.

therefore 91/46.068 (mm ethanol) = moles of ethanol = 1.975 moles

since ethanol 1:3 with water

3x1.975 moles = 5.926 moles of water

5.926 x mm water (18 around ish) = 106.67g of water formed.

Since 1g of water = 1mL therefore 106.67 mL of water.

 

[Drsoccerball]

re: HSC Chemistry Marathon Archive

Just sat chem half yearly D: wtf what ethanoic acid made from like substances and graph them over the temperature...

 

[enigma_1]

re: HSC Chemistry Marathon Archive

Just sat chem half yearly D: wtf what ethanoic acid made from like substances and graph them over the temperature...

wat

 

[Ekman]

re: HSC Chemistry Marathon Archive

I believe he is talking about Acetic Acid. The question was: "State the four chemicals in an acetic acid solution." After that it asked: "Sketch a curve based on temperature and concentration of the acetic acid solution". The question gave the pH of the acetic solution as temperature increased in a tabulated format.

The question about the ethanoic acid was based on the back-titration of CaCO3. The question said that instead of reacting CaCO3 with excess HCl then titrating the remaining moles using NaOH, in order to find the mass composition of CaCO3 in a substance, what are the effects or impacts when you replace the HCl with ethanoic acid and explain your reasoning.

 

[Kaido]

re: HSC Chemistry Marathon Archive

Woah half yearlies already? It's only week 6 :O
Which school is this?

 

[Ekman]

re: HSC Chemistry Marathon Archive

Woah half yearlies already? It's only week 6 :O
Which school is this?

We have Ext 1 and 2 math next week as well....