VCE Chemistry Question Thread

[smiley123]

Pretty sure that's it. If you think about it, potassium dichromate isn't probably gonna stick toegher in solution, so the ions effectively do act independently of one another

But in K2Cr2O7, K2 is +1, and Cr2O7 is -2, there is no change in valency when the ions are split.

[geminii]

Hey, this is a Unit 1/2 Question

If they ask you to draw the isomers of something, how would you draw them? Like how would you know how to draw them? And are there certain compounds that have isomers while others don't? And how do you identify between them if so?

Thanks so much, sorry if the answer to the question is really simple!

[Elizawei]

P-O-P

I always call them pop bonds in my head :p

Ahhh thanks for that nifty acronym!

[Elizawei]

Name the type of bonding that is present between a deoxyribose molecule and phosphate molecule

I thought it was phosphodiester bond? but the answers says hydrogen bonding

[Swagadaktal]

Name the type of bonding that is present between a deoxyribose molecule and phosphate molecule

I thought it was phosphodiester bond? but the answers says hydrogen bonding

Is it called a phosphodiester bond in chemistry? I don't remember using that term for any questions.
But yeah I think you're right - it's a covalent bond between the two so no chance it's hydrogen bond.

[JellyBeanz]

Name the type of bonding that is present between a deoxyribose molecule and phosphate molecule

I thought it was phosphodiester bond? but the answers says hydrogen bonding

Yeah, i always thought it was a phosphodiester bond because when the phosphate molecule bonds with the deoxyribose, it loses a water molecule (condensation) and the oxygen bonds with the carbon from the deoxyribose. I'm not sure how it's a hydrogen bond.

[sweetcheeks]

Where is everyone up to in chemistry? I've finished the theory for unit 3 and am just revising for the next 2 weeks until the final SAC.

[HopefulLawStudent]

We're up to biofuels.

[vox nihili]

Yeah, i always thought it was a phosphodiester bond because when the phosphate molecule bonds with the deoxyribose, it loses a water molecule (condensation) and the oxygen bonds with the carbon from the deoxyribose. I'm not sure how it's a hydrogen bond.

I'm fairly confident that's a mistake. It is a phosphodiester.

[Elizawei]

Yup yeah it was one of those commercial unit 3 exams..

Thanks for the clarification guys! Thought I was going delusional for a bit

Where is everyone up to in chemistry?

Yeah same here I just finished unit 3 content, got a biomolecules/aspirin/instruments sac next week and a unit 3 trial exam tomorrow  

[lzxnl]

Yup yeah it was one of those commercial unit 3 exams..

Thanks for the clarification guys! Thought I was going delusional for a bit
Yeah same here I just finished unit 3 content, got a biomolecules/aspirin/instruments sac next week and a unit 3 trial exam tomorrow

If it makes you feel better, I don't like commercial exams for that reason. They're often mistaken. One exam said that a solution of 1 M KF would be neutral, when any informed chemistry student looking at the VCE data booklet would know that its conjugate acid is a weak (but not too weak) acid, so KF must be basic.

In their defence, VCAA has given stupid numbers before. They once wrote the equilibrium constant for H₂ + F₂ -> 2HF had a 3 digit equilibrium constant. In reality, the natural log of the equilibrium constant was closer to the number they had in mind.

[kimmytaaa]

Has anyone done their sac amino acid?

[HopefulLawStudent]

quick question: What is the role of concentrated sulfuric acid in esterification reactions?

Would a sufficient answer for a SAC/exam situation be that: Concentrated sulfuric acid catalyses the esterification reaction, increasing the rate of reaction?

[Syndicate]

quick question: What is the role of concentrated sulfuric acid in esterification reactions?

Would a sufficient answer for a SAC/exam situation be that: Concentrated sulfuric acid catalyses the esterification reaction, increasing the rate of reaction?

Yes, and also that it isn't directly involved in the reaction, as it does not change the product in anyway.

[Swagadaktal]

quick question: What is the role of concentrated sulfuric acid in esterification reactions?

Would a sufficient answer for a SAC/exam situation be that: Concentrated sulfuric acid catalyses the esterification reaction, increasing the rate of reaction?

For now yes.

Apparently we learn more about the reaction in unit 4 chemistry so in the exam I don't think that would be sufficient. But I haven't done unit 4 yet so I'm not certain