# BoS trials Maths and Chemistry 2022 (1 Viewer)

#### Trebla

Want some valuable exposure to harder questions for the HSC exam?

Want to do a practice paper under simulated exam conditions in preparation for your HSC?

Know anyone at school who is a gun at HSC maths and/or HSC chemistry?

It is that time of year again! This year, Bored of Studies will be holding trial exams for:

Mathematics Extension 1
Mathematics Extension 2
Chemistry

These are aimed at students seeking a challenging paper that will push their limits on how well they really know their stuff. The exams have been designed by our team maintaining a high standard of challenging questions, whilst still remaining within the bounds of the HSC syllabus.

They will interest you, challenge you and show you different ways of thinking for certain topics (which will be very handy for the actual HSC exam!). Students who have taken these trial exams in previous years can attest to this. Also, this will be one of your last chances to practice a full exam as close to HSC exam conditions as possible.

Note: These are not your average trial papers. These papers are skewed towards the more challenging questions (i.e. without most of the boring/repetitive easy stuff in a typical trial paper). Students who may be worried about losing motivation after attempting the paper are reminded that this is NOT intended to be an accurate reflection of the difficulty of the HSC.

Time of the exams
The below times are the scheduled exam times (including reading time). It is recommended that you arrive at least 10 minutes prior.
Mathematics Extension 2
Tuesday 4th of October
9:50am - 1:00pm

Mathematics Extension 1
Tuesday 4th of October

2:30pm - 4:40pm
Chemistry
Wednesday 5th of October

1.30pm - 4.35pm

Place of the exams
All exams will take place at the Sydney Centre of Mathematics in Paramatta, which is only a 5 minute walk from Parramatta station.
Sydney Centre of Mathematics
Level 3/2 Wentworth St
Parramatta NSW 2150

Target audience
It is highly recommended that students attempting the papers are sitting in the band 6 or band E4 range (or at least aiming for that). The exams will very thoroughly assess your understanding of different topics, but more importantly your ability to apply this to solving problems under exam conditions.

What to bring
The usual materials allowed for the HSC exams, including pen and calculator. Exam writing booklets will be provided on the day, where applicable. You are also highly encouraged to wear a mask to help reduce the risk of any COVID-19 transmission.

Cost
We kindly ask that you each donate just \$10 (cash only) to partially cover our printing costs. If you are doing multiple papers you only need to pay once. The rest comes out of our own pockets. Contrary to what you might hear, we are actually NOT paid to put the time and resources into designing the paper and marking your responses. It is purely out of our passion to offer you guys something unique and valuable for your studies.

How to register
Please send me a private message (here or click on "Start a new conversation" on my profile) stating the following for each attendee:
• Name
• School
• Which exam(s) you will be sitting (Maths Ext1, Maths Ext2, Chemistry)
You must have a Bored of Studies account to register. If you do not have an account, I encourage you to make one (it's free!).

Please ensure that you keep an eye on this thread for any key updates and releases of the exam paper, solutions and marks.

If you wish to invite some friends (which I encourage provided they fit the recommended target audience described above), you may register on their behalf by providing their details as well. If you know anybody who is ‘beast’ at Mathematics and/or Chemistry, I ask that you link them to this page. We want to put the best people in the state up against each other for this exam. Consider it a challenge from us.

Note that we do have a registration cap of 50 people for each exam, so get in quick!

Once you have registered, you will receive a student number to confirm your registration. Keep this student number with you for each exam. You can use it to track your results when I put the marks online (only the student number and marks will be shown). You are only registered when I have replied with your student number. Please be patient as it takes time for me to get through all the registrations.

Past exams and solutions

For Maths, we do have past papers since 2012 to give you an idea of what to expect. Keep in the mind that whilst the new syllabus was in place since 2020, the majority of the questions in those past papers are still relevant to the current syllabus.

For Chemistry, we have past papers for 2020 and 2021. Please note that official solutions were not written for the 2021 paper.

Feel free to use them as preparation for this year's paper or just practice in general.

Chemistry
https://www.boredofstudies.org/resources/bos-trial-chemistry-2020-2021-exams-and-solutions.19830/

https://www.boredofstudies.org/resources/bos-trials-mathematics-2013-2015-exams-and-solutions.17177/

Mathematics Extension 1
https://www.boredofstudies.org/reso...ension-1-2012-2021-exams-and-solutions.17484/

Mathematics Extension 2
https://www.boredofstudies.org/reso...ension-2-2012-2021-exams-and-solutions.17485/

Look forward to seeing you there!

#### Trebla

Bump! Still got spots left.

#### Trebla

Only 4 more days to go!

Thanks to everyone who has registered so far! I would like to provide an important update on the registration availability.
• For Mathematics Extension 1, we are almost at full capacity. I will continue to take registrations for this subject up until 11:59pm Friday 30th September. Any expressions of interests that come after then will be put on a reserve list, which will be opened up if any existing registrations can no longer attend.
• For Mathematics Extension 2 and Chemistry, we have plenty of spots remaining and will continue to take registrations at this stage.
If you are no longer able to attend, it is important that you let me know ASAP so that I can:
• Free up more spots for other students who can attend
• Get a more accurate attendance count with respect to printing (we would prefer not to waste our printing costs for no-shows)

#### Trebla

Get excited! Maths is on tomorrow!

Just a reminder of the time and place below. Please arrive at least 10 minutes beforehand.

Mathematics Extension 2
9:50am - 1:00pm

Mathematics Extension 1
2:30pm - 4:40pm

Sydney Centre of Mathematics
Level 3/2 Wentworth St
Parramatta NSW 2150
View attachment 36315

For those registered for Chemistry on Wednesday, please let me know if you can no longer attend ASAP so that I have accurate idea of how much the print costs will be.

#### Trebla

Hi guys,

FYI we’re running a bit behind schedule so please arrive at around 2.50pm for a 3.00pm start.

#### Trebla

Thanks to everyone who attempted the Maths papers today (sorry for the delays in timing)! Hope you enjoyed doing the challenging questions. It was also great to meet some of you in person as well!

Solutions and marking will proceed as usual so your patience is appreciated.

If you have any specific questions you want an answer to in the Maths Ext1 and Maths Ext2 papers, please ask them in this thread.

Just a reminder:
Note: These are not your average trial papers. These papers are skewed towards the more challenging questions (i.e. without most of the boring/repetitive easy stuff in a typical trial paper). Students who may be worried about losing motivation after attempting the paper are reminded that this is NOT intended to be an accurate reflection of the difficulty of the HSC.
For those taking the CHEMISTRY exam tomorrow, please be reminded of the time and place:

Chemistry
1.30pm - 4.35pm
Sydney Centre of Mathematics
Level 3/2 Wentworth St
Parramatta NSW 2150

#### abe123442

##### New Member
Hi,

Just curious about the maths papers but, is there a date by which an online copy of the papers get released?

#### edwxnsamuel

##### New Member
Hi,

Just curious about the maths papers but, is there a date by which an online copy of the papers get released?
Tomorrow hopefully

#### Trebla

Thanks to all those who attended the Chemistry exam today! Hope you got a valuable experience from this exam!

For those who have asked, I will aim to upload the question papers (and make some acknowledgements) by tomorrow.

#### Trebla

Now that the BoS trial events are done, I want to extend my sincere thanks to the rest of the team who helped put the questions and paper together for Maths and Chemistry (in particular to Paradoxica, sharky564, jazz519, Dazzling_Light, IAmWinston and edwxnsamuel).

Also massive thanks to Carrotsticks for allowing us to hold the events at the Sydney Centre of Mathematics venue.

...and now here's what you've all been waiting for.........................................

Please find the papers attached with some minor edits. If you find any minor typos/errors, feel free to call them out for us to consider.

We have commenced the process of solution writing and marking the papers. Please be patient as this will take time to get through and write up (especially given we had more attendees than last year).

In the meantime, we are more than happy to offer answers to any specific questions that you want to know about sooner than later. Just let us know in this thread!

Also, please let us know your thoughts on the papers. Were there any questions you particularly liked/disliked?

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#### edwxnsamuel

##### New Member
Now that the BoS trial events are done, I want to extend my sincere thanks to the rest of the team who helped put the questions and paper together for Maths and Chemistry (in particular to Paradoxica, sharky564, jazz519, Dazzling_Light, IAmWinston and edwxnsamuel).

Also massive thanks to Carrotsticks for allowing us to hold the events at the Sydney Centre of Mathematics venue.

...and now here's what you've all been waiting for.........................................

Please find the papers attached with some minor edits. If you find any minor typos/errors, feel free to call them out for us to consider.

We have commenced the process of solution writing and marking the papers. Please be patient as this will take time to get through and write up (especially given we had more attendees than last year).

In the meantime, we are more than happy to offer answers to any specific questions that you want to know about sooner than later. Just let us know in this thread!

Also, please let us know your thoughts on the papers. Were there any questions you particularly liked/disliked?
@IAmWinston time to mark after paper 2

#### Run hard@thehsc

##### Well-Known Member
May I know the ans the Question 32 in the Chem paper if possible? Thanks!

#### edwxnsamuel

##### New Member
May I know the ans the Question 32 in the Chem paper if possible? Thanks!
Sure! The sample answer is along the lines of:

- Unlikely to contain an alcohol if the solution remains purple upon the addition of acidified KMnO4 (an oxidant that would oxidise primary and secondary alcohols under standard conditions).
- Likely to contain a carboxylic acid if bubbles form upon the addition of NaHCO3 (effervescence with the addition of NaHCO3 to a carboxylic acid is indicative of the production of carbon dioxide gas)

Compound C: Using the previous lines of thought, it must be a carboxylic acid with 2 carbons and no further oxygens, so it must be ethanoic acid (draw structure)

Compound D: A carboxylic acid with 4 carbons, however, with only 2 C13 NMR peaks. This indicates symmetry, and since there are 4 oxygens, we can deduce the compound as butanedioic acid (draw structure).

Compound E: not a carboxylic acid; however, it reacts with succinic acid to form a polymer; which suggests that it contains an alcohol, which is further justified by the decolourisation of acidified KMno4 solution (which would decolourise upon oxidising a primary or secondary alcohol). A linear polymer is formed when reacting succinic acid with a diol, so 3 -OH groups must be present. Since there are 2 C13 NMR peaks, we can deduce that D must be propane-1,2,3-triol (draw structure).

The final polymer (which must be redrawn) is the following (attached below); candidates must show the centre succinic acid, the two attached glycerol, the four attached succinic acid molecules, and the four attached glycerol.

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#### yanujw

##### Well-Known Member
For the Ext. 2 paper, MC question 4, aren't B and D equivalently correct answers?

#### Trebla

For the Ext. 2 paper, MC question 4, aren't B and D equivalently correct answers?
Thanks for picking that up. Edited that in the paper now.

As for the marking, any students who chose (B) will be treated the same as the students who chose (D) for that question.

#### 011235

##### Active Member
I'm interested, how do you do 14a in ext 1? That really threw me..

#### Run hard@thehsc

##### Well-Known Member
I personally did not do the test, but arrived at the answer after substituting x = 2cos(theta), then finding the roots using the cos(3theta) expression. After which I used the manipulation of the sum of roots and double roots. Correct me if I am wrong!

#### dan964

##### what
In Q14(a)(i) in Ext 2 paper, x is missing the subscript?

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#### dan964

##### what
@Trebla
Just a quick question about MX2 Q12(c)(i) and (iii) should distance be considered positive or is a negative value ok?
Should (i) be
$\bg_white d=\frac{|ax+by+cz|}{\sqrt{a^2+b^2+c^2}}$

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#### Trebla

I'm interested, how do you do 14a in ext 1? That really threw me..
In general, when doing a trigonometric substitution to solve a polynomial, there are usually two approaches:
• x = tan θ (which permits x to be any real number as parameter θ varies)
• x = kcos θ or x = ksin θ (which constrains the roots to be between -k and k, so the choice of k is important)
Most HSC questions tell you what substitution to use, but if you were not given that then you would use the general form and then use a bit of inspection to work out an appropriate value of k that leads to the appropriate trig multiple angle formula.

In this question, when you try substitute x = kcos θ, a bit of inspection suggests that k = 2 is appropriate to be able to obtain the triple angle result.

In Q14(a)(i) in Ext 2 paper, is x is missing the subscript?
@Trebla
Just a quick question about MX2 Q12(c)(i) and (iii) should distance be considered positive or is a negative value ok?
Should (i) be
$\bg_white d=\frac{|ax+by+cz|}{\sqrt{a^2+b^2+c^2}}$
Yep, thanks for picking those up. The absolute value is actually missing in the question.

Both will be fixed in a final updated version, once all the marking is done.