VCE Chemistry Question Thread

[BlinkieBill]

Hi
are we supposed to know how to do multiple choice Q14 from NHT VCAA 2017 chem??

100 mL of 0.4 M nitric acid, HNO3, is added to 100 mL of 0.1 M barium hydroxide, Ba(OH)2.
The pH of the resulting solution is

[Bri MT]

Hi
are we supposed to know how to do multiple choice Q14 from NHT VCAA 2017 chem??

100 mL of 0.4 M nitric acid, HNO3, is added to 100 mL of 0.1 M barium hydroxide, Ba(OH)2.
The pH of the resulting solution is

Nope

[BlinkieBill]

Hi
Is this correct for an advantage and disadvantage of biogas as an energy source??
Advantage:
- carbon  neutral - no net release of CO2
Disadvantage:
- low energy content

I feel like i have confused something here.

[Bri MT]

Hi
Is this correct for an advantage and disadvantage of biogas as an energy source??
Advantage:
- carbon  neutral - no net release of CO2
Disadvantage:
- low energy content

I feel like i have confused something here.

Carbon neutral in that the carbon dioxide released by combustion is cancelled out by it being absorbed from the air by the plants' growth. However carbon dioxide would still be released in transport and processing.    (Your statement may or may not get a mark)

A better advantage is that by combusting biogas the amount of methane released into the atmosphere is reduced, and methane contributes much more to global warming per mol than CO2.


Biogas does release less energy per gram than natural gas

[shiba woof woof]

Hey guys

With a SAC average above average (all my teacher is willing to give me), what exam score do i need to get a 25 for chemistry?

And... since electrolysis is too confusing for me, i plan on just not learning it. How much marks do you think this will make me lose in the exam?

Thanks all

[ardria]

With a SAC average above average (all my teacher is willing to give me), what exam score do i need to get a 25 for chemistry?

And... since electrolysis is too confusing for me, i plan on just not learning it. How much marks do you think this will make me lose in the exam?

I would definitely be aiming to score closer to 30 raw, because if you fall short you'll probably still be over 25. If you aim for 25 raw then fall short, it would be such a shame.

It really depends on how lucky you are - how much electrolysis is on the exam is up to VCAA. But it will definitely be on the exam in either multiple choice or short answer or both, and if you're really set on just not learning it at all then you you'll have to be prepared to automatically lose anywhere from ~2 to ~10+ marks. I have no idea if VCAA will put one on this year, but electrolysis short answer questions are quite common. For this reason, I don't think skipping electrolysis entirely is a great idea.

[ardria]

In regards to this question from STAV 2013 Unit 3&4 Exam:
https://i.imgur.com/Z9Kw1vw.png

Do we actually need to know the hydrogencarbonate reaction, and that dichromate changes from orange to green?

[Bri MT]

Hey guys

With a SAC average above average (all my teacher is willing to give me), what exam score do i need to get a 25 for chemistry?

And... since electrolysis is too confusing for me, i plan on just not learning it. How much marks do you think this will make me lose in the exam?

Thanks all

If you get an electrolysis question and it asks you to pick what reacts do this:
Go up on the left side of the EC series until you reach the highest reactant/ (thing that you have in your solution) write this equation down
Go down on the right side of the EC series until you reach the lowest reactant/ (thing that you have in your solution) and write this equation down

These are the half reactions that occur

Even if this is all you remember of electrolysis it should help you get a couple of marks

[uhoh]

What exam scores (approx) for low 30s in chem?
SACs are 65% in a strong cohort with an avg of 80%
I have to makr sure I get a 30 to meet prereqs

[pmmenotes]

Anyone know where i can find solutions to the NHT 2017 Chem exam?

[Apricot]

Can somebody please clarify which resources are best to use for sac revision for 3/4? There's so many like checkpoints, neap smart study questions, AN questions etc and I'm having trouble deciding which resources would be the best to use. 

[Tknight]

Hey everyone, I have a few questions..

Is the percentage by mass formula the same as the percentage yield formula?
such as Mass (calculated) divide mass (given)

[Cassidyhogi]

Hey everyone, I have a few questions..

Is the percentage by mass formula the same as the percentage yield formula?
such as Mass (calculated) divide mass (given)

I get why they might seem similar but they are actually pretty different:
Percentage yield is finding how much of a substance ends up being produced compared to how much should have been produced according to the reaction eqn/mole ratios.
% yield = actual yield (how much actually produced)x100 / theoretic yield (how much should have been produced)

On the other hand, percentsge by mass is how much of a particular substance is in a mixture of something.
For example, you might need to find the sodium content of potato chips.
% by mass of sodium = mass of sodium in chips x100 / mass of chips x100

[Cassidyhogi]

Anyone know where i can find solutions to the NHT 2017 Chem exam?

http://www.vcaa.vic.edu.au/Documents/exams/chemistry/2017/nht/chemistrynht_examrep17.pdf

[SweetJack]

is question 7b in the 2016 exam relevant to this years study design??