General Thoughts (2 Viewers)

[Queenroot]

Did you guys give an example for an acid for that question?

 

[darkness70]

lol but it asked why is it used as a food preservative. It's used as a food preservative because not only does it inhibit bacterial growth but it has an additional feature which is enhancing flavour.

Haha do you know what a preservative is... It makes the food last longer.. Flavoring is different

 

[darkness70]

Did you guys give an example for an acid for that question?

Nope shouldn't matter though

 

[Menomaths]

Did you guys give an example for an acid for that question?

Never asked for one :/

 

[Menomaths]

Haha do you know what a preservative is... It makes the food last longer.. Flavoring is different

Do you know what inhibiting bacterial growth does?

Besides, I explained that point^ in detail, so I can get 2/2 if what you said is correct and I can get 2/2 if what I said is correct. Just being on the safe side y'know.

 

[Buwwy]

what did people write for why acids are used in food preservatives?

I wrote something like: they kill the micro organisms that spoil the food and used as antioxidants to prevent the oxidation of oils which helps preserve the food. Don't think I described it though :/

 

[KoshX87]

Did you guys give an example for an acid for that question?

I said citric acid, and it makes it sour too.

 

[RealiseNothing]

I said citric acid, and it makes it sour too.

Yep I said sour and sharp iirc.

 

[darkness70]

What would you guys predict my HSC mark if I got around 85 raw? (Pretty sure I got higher but worst case scenario). And I think E4 cut off could be a bit higher like mid 70s

 

[Queenroot]

What would you guys predict my HSC mark if I got around 85 raw? (Pretty sure I got higher but worst case scenario). And I think E4 cut off could be a bit higher like mid 70s

probs like 98

 

[AnimeX]

what did you guys put for the "is this reaction spontaneous" question? for the one between bromine and chrlorine

 

[darkness70]

probs like 98

I think that's a bit high.. Haha according to realize, that's first in state

 

[bangladesh]

what did you guys put for the "is this reaction spontaneous" question? for the one between bromine and chrlorine

Yes. It's because one is more reactive and displaces the other one out of the solution.

 

[darkness70]

what did you guys put for the "is this reaction spontaneous" question? for the one between bromine and chrlorine

It's not, you had to use the standard potentials table and you'll get a negative answer for the E cell, like -0.34 or something can't remember, meaning you have to supply voltage

 

[darkness70]

Yes. It's because one is more reactive and displaces the other one out of the solution.

Wth aren't you meant to use reduction and oxidation

 

[superSAIyan2]

what did people write for why acids are used in food preservatives?

i said acids are used as preservatives since they lower the pH of foods. This inactivates enzymes and kills microorganisms responsible for food spoilage as they are denatured at low pH. Thus the acid increases shelf life of food

 

[superSAIyan2]

what did you guys put for the "is this reaction spontaneous" question? for the one between bromine and chrlorine

In the reaction chloride ions are oxidised to chlorine gas and bromine liquids is reduced to bromide ions.
Anode: 2Cl(-) ----> Cl2 + 2e- E(oxidation) = -1.36V
Cathode: Br2 + 2e- ----> Br- E(reduction) = 1.08V
cell potential is -0.28V <0 therefore nonspontanteous

 

[Makematics]

How many marks was that worth? Im getting 0 for that

 

[AnimeX]

How many marks was that worth? Im getting 0 for that

yeah me too... didn't even see it as oxidation/reduction, i just said they both needed one electron for full shell therefore not sponaneous...

 

[darkness70]

In the reaction chloride ions are oxidised to chlorine gas and bromine liquids is reduced to bromide ions.
Anode: 2Cl(-) ----> Cl2 + 2e- E(oxidation) = -1.36V
Cathode: Br2 + 2e- ----> Br- E(reduction) = 1.08V
cell potential is -0.28V <0 therefore nonspontanteous

^