Question Chain Thread !!! (1 Viewer)

[JasonNg1025]

Explain the issues with Arrhenius' definition of acids

Arrhenius stated that acids dissosciated into ions in aqueous solutions, producing the H⁺ ion, and bases produced the OH^- ion in water. However, there were limitations with this theory. His definition could not explain how non aqueous solutions can be acidic or basic. He also could not explain how salts can be acidic or basic. Also, Arrhenius could not explain amphoteric substances.

 

[Azreil]

Everywhere? It's general knowledge, great to know it some random situations

EDIT: I actually remember doing it in year 11

In Year 11 we got tables dammit.

WTB Tables.

Describe a test you performed to monitor water quality levels.

 

[hoochiscrazy]

Everywhere? It's general knowledge, great to know it some random situations

EDIT: I actually remember doing it in year 11

K thanks thought it might be the case. Havnt come across it cuz been studying straight from the dot points.

Anyone do forensic's as there option??? Or you guys stick with the more popular topis---industrial/shipwrecks?

 

[JasonNg1025]

Describe a test you performed to monitor water quality levels.

Turbidity is easiest. A small white piece of paper with a black cross drawn on it was put under a calibrated cylinder. The cylinder was filled until the black cross "disappeared" from view. The calibrations were used to determine the amount of undissolved solids.

 

[Azreil]

Question: Do you think we should know the equations for the Winkler's method of titration?

EDIT: I do Shipwrecks. I hate Shipwrecks. I am insanely jealous of you doing Forensics.

 

[JasonNg1025]

I do industrial
Is forensics fun?
I hope we don't need to know the winkler method cause I got no idea :O

 

[SkimDawg]

A bit off-topic, what is the most popular optional topic?

 

[danz90]

I do industrial
Is forensics fun?
I hope we don't need to know the winkler method cause I got no idea :O

I hope not either... I don't know each exact step of the winkler method.

A bit off-topic, what is the most popular optional topic?

Industrial Chem, followed by shipwrecks.

 

[hoochiscrazy]

I do industrial
Is forensics fun?
I hope we don't need to know the winkler method cause I got no idea :O

Our teacher was once a forensic investigator so was alright. She showed us heaps of stuff from her old job and told us whole bunch of nasty stories so didnt get that much learning done. Bad thing is that since so little ppl do this option hard to find some decent notes.

For a biopolymer is the name biopol enough or do you need to know the actual chemical name?

 

[JasonNg1025]

Who here is feeling like me....
You really want to study, but then when you try you seem to know it so you get easily distracted

 

[Azreil]

I know the gist of it... you add starch and crap... but I have no idea for the equations.

If you two don't know it, I'm not going to bother studying it xD

Describe the impact of increased temperature on the production of ammonia.

EDIT: Oh yes. Oh, oh yes. I look at things and am like "Oh I know that!" and then I wander off topic.

On that note, give me questions! =P

 

[JasonNg1025]

For a biopolymer is the name biopol enough or do you need to know the actual chemical name?

Name should be enough, but it's more impressive if you know the chemical name as well. If they ask you a question about a biopolymer being a future resource or something, if you give a good enough response for the question they shouldn't pennalise you for not giving the chemical name

 

[JasonNg1025]

Describe the impact of increased temperature on the production of ammonia.

Ammonia production by the Haber process is exothermic. This means it releases heat. Therefore by Le Chatelier's principle ammonia yield decreases from an increased temperature. However, a decent reaction rate is only achieved by a higher temperature, hence a compromise is needed. Usually, a temperature from around 400^o C to 500^o C is used.

EDIT: Fine I'll give you questions. *Flicks randomly at dot point book like I've been doing all morning*

Ok, explain why a small amount of CFC can break down thousands of ozone molecules

Offtopic edit: lol I want a pizza after seeing that ad
Anyone else getting that ad?

 

[hoochiscrazy]

Name should be enough, but it's more impressive if you know the chemical name as well. If they ask you a question about a biopolymer being a future resource or something, if you give a good enough response for the question they shouldn't pennalise you for not giving the chemical name

K thanks. really couldnt be bothered learning the chemical name.

HSC 2010 :/ for real???

 

[JasonNg1025]

Yes

 

[danz90]

Ammonia production by the Haber process is exothermic. This means it releases heat. Therefore by Le Chatelier's principle ammonia yield decreases from an increased temperature. However, a decent reaction rate is only achieved by a higher temperature, hence a compromise is needed. Usually, a temperature from around 400^o C to 500^o C is used.

EDIT: Fine I'll give you questions. *Flicks randomly at dot point book like I've been doing all morning*

Ok, explain why a small amount of CFC can break down thousands of ozone molecules

Offtopic edit: lol I want a pizza after seeing that ad
Anyone else getting that ad?

When one CFC molecule reaches the stratosphere, it photodissociates under UV Radiation, releasing a chlorine free radical:

CF₃Cl ---UV---> CF3 + Cl'

Chlorine radicals then attack ozone molecules:

Cl' + O₃ ---> ClO' + O₂

ClO' radicals then combine with monatomic oxygen present:

ClO' + O' ---> Cl' + O₂

Since Cl' is continuously regenerated, as shown above. The presence of one CFC molecule catalyses the destruction of thousands of ozone molecules.

 

[eddy11]

whats winklers method of titration, i do shipwrecks and ive never heard of it, and yeah, i think i know most of the stuff now, its in long term memory, im excited, but i have a question:

Describe the recent discovery of elements

 

[Azreil]

Booo missed it. Was too busy freaking out that I'd forgotten the definitions of acids.

Man I'm dumb sometimes.

A solution is clear in phenolphtathlein and blue in bromothymol blue. In what pH range does the solution lie?

Hey, Jason, how rich would you be if you had a dollar for every time someone asked you that? =P

 

[Azreil]

whats winklers method of titration, i do shipwrecks and ive never heard of it

Not to do with Shipwrecks. Is a method of quantitatively measuring the dissolved oxygen in a sample of water.

 

[JasonNg1025]

Fine.. Deduce why different metals produce different colours during flame tests