Option: Industrial Chemistry (1 Viewer)

[clockwise]

That prac question was weird man. I thought the model the eqm was that stupid thing where we used 5ml and 10ml pipette with water and transfered into cylinders thing but there are like absolutely NO risks associated and with the saponification thing my teacher was like dont talk about detergents because they have absolutely NOTHING to do with saponification, something about they're made from petrochemicals adn alkanols or something like that.

 

[Fish Sauce]

phew. i was freaking out about that question.

what did you guys put for the seperation in the solvay process? apparently it's done by crystallization but i just said one was solid and one was aqueous.

I put filtration because in the diagram it had them both going to a box marked filter and I had nfi how it worked, lol. Hopefully I manage one mark considering it was a two mark question.

 

[Armenikum]

I put filtration because in the diagram it had them both going to a box marked filter and I had nfi how it worked, lol. Hopefully I manage one mark considering it was a two mark question.

Nvm, I was getting confused - it's amazing how much you forget the next day!

 

[dwatt]

Yes, my mistake on that.

In DOTPOINT they distinguish the mdoel from the qualitatively analyse by the using NO2 one for the qualitative, and beads for the model.

Yeah - that seems to be what they were after. I talked to my teacher about it, and he said that you might lose some marks for doing a NO2 example. But he said, in essence, you are still demonstrating what happens to equilibrium systems in a clearly macroscopic way (colour change), so ppl who did that or iron thiocyanate, or any real prac (rather than a model) will not get 0/6!

So all is not lost, 4/6 will do me fine, and hopefully they will not penalise heavily if you outline a valid experiment, discuss a limitation and safety issue.

 

[dwatt]

No way would u lose 5 marks, 2 marks for usng the wrong exp, if ur risks and limitations were sufficient they should give u marks for them.

Also with the solvay thing, dont they hav to cool nahco3 b4 it becomes insoluable, as its slightly soluable at high temps (and even room temp), has to b cooled to a few degrees i think b4 it ppts out.

Yeah the insolubility of NaHCO3 at low temps was about the only bit of chemistry knowledge required.

Shame...there was so much more GOOD chemistry they could have asked about. Instead we get comphrehension, models and environmental impacts.

 

[jah_lu]

model means not a real equil. experiment
the no2 one is not a model
its an equil itself
the one i used was 2 measuring cylinders and 2 pipettes transferring water from one to another
im not sure but because it was divided up into 3 q (2marks 1mark 3 marks), if you did not write about a model
i think you've already lost 6 marks there
as you wont meet the criteria (i suspect the criteria for one mark is name a model)
so if you dont even name a model you cant even get 1

saponification is only for soaps
detergents are made from oil
4 marks for industry and environment
im guessing as there are 2 products
1 mark each for soaps-industry and env
and for glycerol 1 mark each as well

you cant say filter
because sodium hydrogen carbonate (like all group 1 salts) is soluble in water
you wont get a precipitate if there is no solid
you have to cool it to 5 degrees where it will crystallise out because of low solubility at low temperatures

 

[candybink]

The weird thing was, there were no questions on sulfuric acid!
How much did everyone write for sodium hydroxide production, i wrote nearly two pages...

 

[dwatt]

model means not a real equil. experiment
the no2 one is not a model
its an equil itself
the one i used was 2 measuring cylinders and 2 pipettes transferring water from one to another
im not sure but because it was divided up into 3 q (2marks 1mark 3 marks), if you did not write about a model
i think you've already lost 6 marks there
as you wont meet the criteria (i suspect the criteria for one mark is name a model)
so if you dont even name a model you cant even get 1

saponification is only for soaps
detergents are made from oil
4 marks for industry and environment
im guessing as there are 2 products
1 mark each for soaps-industry and env
and for glycerol 1 mark each as well

you cant say filter
because sodium hydrogen carbonate (like all group 1 salts) is soluble in water
you wont get a precipitate if there is no solid
you have to cool it to 5 degrees where it will crystallise out because of low solubility at low temperatures

I hope I get at least a few marks. Who knows. The teacher I've spoken to thinks it may be worth a few, depending on the criteria.

I don't know where BOS got that soap question from. The only dot point I found related is this:

"Solve problems, and use available evidence to discuss, using examples, the environmental impacts of the use of soaps and detergents"

That dot point has NO mention of glycerol. That dot point does not mention impacts on society either. I understand that saponification products means "glycerol and soap", but I thought it was illegal for BOS to assess something that was not outlined in a syllabus statement.

Does anyone know why we would have had to do glycerol and societal impacts? Did I miss a dot point?

 

[Jessica14]

You mean qualitative?


so what the hell would it have been then? the CO2 in soft drink?

I did the CO2 in the soft drink bottle....

 

[conroy1234]

I didnt talk about synthetic detergents because I didnt know you could make them from Saponification - I thought it was only appropriate to talk about Soap and its structure. I could be wrong an miss out on a mark or two. I did however make reference to Soap is better than synthetic detergents which include phosporous in their builders, which when washed into water ways can lead to algal blooms and eutrophication.

So again, did we need to talk about synthetic detergents?

i don't think we needed to talk about them, cos they're not made by saponification

they're made from hydrocarbon chains from petroleum....or something like that

but yeah it was only a 4 mark question or something like that so just soap by itself would be fine i guess

 

[dwatt]

What ill effects does soap have on the environment anyway? I always thought soap had minimal effect, and its synthetic replacements were the ones that did.


That led me to talk about them! Probably shouldn't have by the sounds of it.

 

[ssglain]

Yeah I got 1.333...

That seems to be the general consensus so you should feel pretty safe.

Same here, but the question specified a temperature of 373K - which is higher than SLC. The equilibrium constant is affected by temperature so how much influence would that have on the value of our calculation?

 

[Fish Sauce]

Same here, but the question specified a temperature of 373K - which is higher than SLC. The equilibrium constant is affected by temperature so how much influence would that have on the value of our calculation?

Good point. The only thing is how are we supposed to know exactly how much the value would change? Not a fair question if we're supposed to take that into account. The syllabus only says we need to know the effect on a K value of a change in temperature, which is that it gets higher or lower. Nothing about calculations.

 

[joshuajspence]

Same here, but the question specified a temperature of 373K - which is higher than SLC. The equilibrium constant is affected by temperature so how much influence would that have on the value of our calculation?

The temperature didnt affect calculations at all. We were given the concentrations, and simply used those as we usually would to calculate the equilibrium constant, K.

I think 373K was put there to test whether people understood the theory and see if anyone was fooled.

 

[claudia b]

I thought the Industrial Chemistry was very poor.

The first question...asked you for the NAME of the Solvay process and the overall reaction. Sheesh.

And the second part, bascially asked you how a solid substance is separated from an aqeueous substance. The diagram provided even had a little box called "filter".

I'm pissed off about that "modelling" of an equilibrium reaction. I read the "risk" part and unfortunately immediately thought about the NO2 prac. That's 5 freakin marks.

yeah... I stuffed up that modelling equilibrium thing... there goes my band 6

 

[JoshyPutts07]

What ill effects does soap have on the environment anyway? I always thought soap had minimal effect, and its synthetic replacements were the ones that did.


That led me to talk about them! Probably shouldn't have by the sounds of it.

I think it was just the fact that it forms a "scum" precipitate with hard water (both mg and ca ions)...........

 

[dairyfarmer]

i think you guys may have go tthat equilibrium question wrong..only because modelling and qualitative analysis are completely different..the qualitative test was the reactionc etc..however modelling is the physical representation of an equilibrium reaction..hence there is a peg model or there is also the people walking in and out of the room model.

 

[Tsuska]

What ill effects does soap have on the environment anyway? I always thought soap had minimal effect, and its synthetic replacements were the ones that did.


That led me to talk about them! Probably shouldn't have by the sounds of it.

Well to society it had a lot of effects (cleaning agent, surfactant etc.) Which led to developments of synthetic detergents which may have phosphates, nitrates causing algal blooms.

But one thing that happens with all Soaps and Detergents is that they are surfactants. Which decrease surface tension which may disrupt marine life. Can kill some marine life and also insects.

And i can't really remember what the question was but yea...just keep talking about random stuff like that =P

 

[nogihenkotoba]

I didn't do the modelling equilibrium one well either, we had 2 diif size measuring cylinders and a straw and just moved water back&forth until the vol. didn't change. But risk? Um, water spillage?
It took too long to remember it in the first place, so I didn't have time to write everything about it down.