VCE Chemistry Free Trial Exam (2017) - written by me!

[Phenomenol]

Alright, I just got home so I'll answer these questions now.

Hi there! Thank you for writing this Phenomenol!! Could someone please explain Q18 of the MC questions? Thank you.

Here is what I have said in the suggested solutions - I have some further comments afterwards.

Each battery provides 1 V, therefore under standard conditions no reaction occurs in the case of the
Zn(NO₃)₂ cell as a voltage of at least 1.99 V is required according to the electrochemical series.
Since the reduction of one Ag⁺ requires one electron, and the reduction of one Cu²⁺ requires two electrons,
n(Ag) will be double that of n(Cu). And because the molar mass of Ag > molar mass of Cu, the mass of
Ag will also be greater than the mass of Cu. Therefore D is correct.

The premise of this question is that you have the reduction of metal ions to solid metal occurring in each cell, if able.
The reduction reaction will be: M^x+ + xe^- -> M, where x is the charge of the metal ion.
The oxidation reaction will be: 2H₂O -> O₂ + 4H⁺ + 4e^-

The battery must supply a voltage of at least the difference in the reduction half-potentials for this redox reaction to proceed.
In the Ag cell, the required voltage is 0.53 V.
In the Zn cell, the required voltage is 1.99 V.
In the Cu cell, the required voltage is 0.89 V.

So if a 1 V battery is connected to each cell... nothing happens in the second cell! So the mass of Zn deposited is 0.
For the other two cells, you can determine the relative masses of both metals deposited in the same duration by both the amount ratio between electrons/each metal, and the molar mass of each metal.

Hope this helps. If you want further elaboration let me know!

This is a great exam thank you
But question 6 multiple choice the definition of a condensation reaction is that water introduced but this is not shown in the reaction so doesn't this technically mean it is not a condensation reaction?

I'm glad you asked this. A condensation reaction is not defined by the formation of water as a byproduct. A condensation reaction in the strictest sense is a reaction between two functional groups in separate organic compounds, combining to form a larger compound and a small byproduct. In the case of Q6 this small byproduct would be ethanoic acid.

Hi I can't seem to find the solutions, could someone please post them again? Thank you!

Strange. I have attached them again in this post. Let me know if you still can't access it.

OMG THANKYOU KIND STRANGER!! Just finished it. Took half an hour longer though
I feel so sad  because I don't want to let myself down in this final, very important, exam.

You're very welcome!
This exam was designed to be pretty hard! Don't worry about it

Hello
I'm really confused with Question 4b, about the two reactions to convert the triglyceride into biodiesel, using ethanol.
1. isn't biodiesal usually a methyl ester, not using ethanol?

Biodiesel can be either methyl or ethyl esters from what I've gathered. Ethyl esters may be more uncommon.

2. isn't it one reaction- transesterfercation- to turn the triglyceride to three biodiesel molecules + glycerol? (heinnamann textbook pg 26)

I think Iasisdabomb's response is a very good one.

Question 1 from multiple choice has confused me. Since the system cannot partially oppose the change in volume, wouldn't diluting the equilibrium solution also decrease the concentration of MgBr2? Not because we have changed the Equilibrium constant, but because we merely increased the volume of the whole solution??

Ah yes. I have tried to make it clear that I am talking about the change after time t - in other words, not the immediate change at time t, but the gradual change that occurs after. Hope that clarifies things.

Perhaps this question is a bit convoluted if enough people complain about it I will do something to fix this.

[wij0020]

Thank you so much Phenomenol!!! 

[Phenomenol]

Thank you so much Phenomenol!!! 

No problem!

I wish everyone GOOD LUCK for tomorrow's exam!! I hope you have benefited from the help given on the ATAR Notes forum. Give it your all and don't look back on it!

If you like what you learned this year then I strongly recommend taking a chemistry subject in your first year at uni if convenient

[manthila2000]

Thanks for this man. It’s very helpful considering there aren’t many practice exams on this study design. 😅

[nononono12345]

how do i access it

[AngelWings]

how do i access it

Have you tried going to the first post on the first page and downloading the attachments? You can try clicking the link (the blue words with the underline) at the bottom of the first post of this thread, which should either ask permission to download or automatically download the files.

[ksel03]

just discovered this... sooo good... thxxx

[David Miot]

[Erutepa]

didn't like the exam. Q9 was poorly done and Q8 was even cacca

Hey David!
I noticed you comment was fairly negative. The forums here try to be a positive place where people can learn and feel comfortable and stating that questions are poorly written detracts from this environment we try to foster. You can by all means think that a question from this exam is flawed or could be improved - but frame this criticism in a way that someone can learn from. Maybe you think the content assessed in the question is irrelevant - then you can say that you think the question is a bit out of the scope of the study design. This is much better than just calling the question poorly written.
Also consider that this practice exam was voluntarily written by a user here on the forums. It most certainly was a very kind gesture for them to invest the time into creating this practice exam, so it would be nice if kindness was extended back to them when giving feedback. To add to this, when users create resources to share here no one should expect them to be 100% perfect - not even professionally made resources are 100% perfect, so its important to recognize this fact and not harshly judge people for making mistakes.

Don't take this as myself not valuing your input - Everyone's input is welcome - I'm just asking that in future you frame any criticisms more constructively and appreciate the effort people put into creating resources.