Learners' Lodge Bulletin

Issue: 001

Content

(Click on the titles below to start reading)

Season Greetings

Space Travel & Rocket Fuel

Air Travel with Bicycles

Influenza or Influencers?

Airline Over-booking

Get to Know Our Staff

Stay Updated

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JC Magazine header 1

JC Magazine side 2Happy holidays! Welcome to the inaugural issue of the Learners’ Lodge Bulletin!

In the past year with us, you would have learnt various concepts in the different subject classes. In this bulletin, you will discover how these concepts can be applied in the real world. It is our vision as tuition teachers to make our subject more interesting and relevant to you, while concurrently preparing you for the A Levels in a purposeful manner.

As a Learners’ Lodge initiative, each issue of our bulletin will include contributions by our very own subject tutors.

For this issue, we would like to take you on a dive into the air (or space) travel industry and show you how some of the concepts you have learnt this year can be used to explain some real-world observations that you might have.

If you have suggestions on content and issues you would like to see in future our bulletin, feel free to contact your tutors or centre managers! Those who would like to flex their creative writing skills can also submit articles. Your input is greatly welcomed and will be acknowledged (or even rewarded, see below!).

Submit and win!
We are looking for a creative name to replace the current one!
Come up with a name that is both relatable (to students) and aptly describe this magazine, and you could stand a chance to win a $20 Uniqlo voucher. The chosen name will be published next issue.

Write in your suggestion to

[email protected]


Only available for existing Learners’ Lodge student |
1 entry per student only | Submission dateline: 3 January 2023, 23:00 | Winner will be contacted after 04 January 2023

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Space travel & Rocket Fuel: Hydrazine

By Mr David Wong

In 2021, Jeff Bezos and Richard Branson kicked off a commercial space race by blasting into the upper atmosphere within weeks of each other, since then, the global space tourism market is skyrocketing, with dozens of companies now offering reservations for everything from zero-pressure balloon trips to astronaut boot camps and simulated zero-gravity flights. The financial services company UBS estimates the space travel market will be worth $3 billion by 2030.

With such increasing demand, the cost of rocket fuel is bound to increase. A very common rocket fuel used is Hydrazine, often used as a low-power monopropellant for the manoeuvring thrusters of spacecraft and also used in terminal descent of spacecraft such as Mars landers Phoenix (May 2008), Curiosity (August 2012) and Perseverance (February 2021).

In all hydrazine mono-propellant engines, the hydrazine is passed over a catalyst such as iridium metal supported by high-surface-area alumina (aluminium oxide), which causes it to decompose into ammonia, nitrogen gas, and hydrogen gas according to the following reactions:

  1. N2H4(l) → N2 (g) + 2 H2(g)
  2. 3 N2H4(l) → 4 NH3 + N2(g)
  3. 4 NH3(g) + N2H4(l) → 3 N2(g) + 8 H2(g)

The first two reactions are extremely exothermic while the third reaction is endothermic. Here is an example of how one’s knowledge on JC1 Physical Chemistry Chemical Bonding and Chemical Energetics, can allow one to actually calculate the energy content of the hydrazine fuel and also to determine molecular shape of the molecule.

(a) Firstly, using valence shell electron pair repulsion theory, one can determine the shape of N in hydrazine.

Each N has 3 electron domains (3 bond pairs and 1 lone pair). To minimize repulsion they are arranged in tetrahedrally. As lone pair is not observed in the shape, each N is trigonal pyramidal in shape.

(b) Secondly, assuming the enthalpy of vaporisation of hydrazine is +44.8 kJ/mol. One can use the bond enthalpies values in the A-level Data Booklet to calculate the enthalpies of reactions 1 to 3.

∆H1 = +∆Hvap+BE(N-N+4N-H)
-BE(N≡N+4H-H)
=+44.8+[160+4(390)] -[944 +4(436)] =-932KJ/mol

∆H2 = +∆Hvap+BE(3N-N+12N-H)
-BE(12N-H+N≡N)
=+3(44.8)+[3(160)+12(390)] -[12(390)+944] =-330KJ/mol

∆H3 = +∆Hvap+BE(12N-H+N-N+4N-H)
-BE(3N≡N+8H-H)
=+44.8+[12(390)+160+4(390)] -[3(944)+8(436)] =+125KJ/mol

(c) Although the third reaction is endothermic, why is it important for it to happen?

From reaction 3, there is an increase in the number of mol of gases from 4 moles to 11 moles. This means the entropy has increased tremendously. This is particularly important for the pressure built and eventually for the thrust of the rockets.

Hydrazine can be synthesized from ammonia and hydrogen peroxide with a ketone catalyst, in a procedure called the Peroxide process (sometimes called Pechiney-Ugine-Kuhlmann process, the Atofina–PCUK cycle, or ketazine process). The first 4 steps are shown below:

Chemical Equation

Currently, head start students who have learnt Organic Chemistry at Learners’ Lodge, would have acquired some knowledge to recognise functional groups of organic molecules and should show an interest to know about the synthesis and production of hydrazine as shown above. As identifying the type of reactions is often asked in many organic questions, JC2 students should be able to identify them with ease.

Step 1: Butanone(EtMeCO) loses the O, ammonia loses 2H to form water: Condensation.

Step 2: Imine with the C=N bond reacts with hydrogen peroxide: Oxidation.

Step 3: Oxaziridine, a three-membered ring loses the O, ammonia loses 2H to form water: Condensation.

Step 4: Hydrazone reacts with Butanone(EtMeCO), water is removed once again: Condensation.

Submit and win!
Q. In the final step 5, the product in step 4 is known to react with a very common reagent to form hydrazine and 2 moles of butanone.
Identify the type of reaction occurred and write a balanced equation.

Submit your answer to
[email protected]
and stand to win a Chicha Sanchen drink voucher*


Prizes are only for existing Learners’ Lodge student |  After the submission dateline, answer will be release to all who wrote in | 3 prizes to be won | 1 entry per student | Answers will be vetted by the author | Only the correct answers will be entered into the draw | Submission dateline: 3 January 2023, 23:00 | Winner will be contacted after 04 January 2023

JC Magazine header 4

Air travel with Bicycles

By Mr David Wong

Covid-19 brought about a dramatic increase in bicycle sales in response to the pandemic. Heightened anxiety over public transportation and a surge in exercise has meant that more are choosing to use one of the most basic forms of mobility, leading to a so-called “bike boom”. And with easing of covid restrictions for travel, more new cycling enthusiasts are travelling with their bicycles on the planes but are nervous about the packing and find it very cumbersome to deflate the tyres as they may wish to ride upon immediate arrival of their destination. Here is an example of how one’s knowledge on JC1 Physical Chemistry, The Gaseous State, can make the experience a lot easier.

Most bicycles have safety instructions. For example, one bicycle has a safety note which reads ‘The maximum internal pressure of the tyre is 8 bar and it will burst if there is a large difference between the internal and the external pressure.’ Assuming the inflated bicycle tyre at sea level (atmospheric pressure 101 kPa) contains 670 cm3 of air at an internal pressure of 6 bar at 20oC. [1 bar = 100k Pa]. The bicycle, with the same tyre inflated at sea level as described above, is usually placed in the luggage hold of the airliner, with typical conditions at a height of 10 000m of 5oC and a pressure of 0.28 bar. Some airlines request for deflation of the bicycle tyres before the flight.

Let us see if this cyclist needs to deflate the tyre before the flight!

(a) Firstly, one can use ideal gas equation, pV = nRT to calculate the number of moles of air in the tyre at sea level.

n = PV/RT
= 600 x 103x 670 x10-6/ 8.31 x 293
=0.165moles

(b) Secondly, assuming that the volume of the tyre is constant, one can calculate the pressure inside the tyre when the airliner is at a height of 10 000m.

Use P1/ T1 = P2/T2
6/293 = P2/278
P2 = 5.69 bar

(c) Thirdly, one should also understand the concept of safety limits so as to prevent the explosion of the tyre on a plane which might have dire consequences. And let us see if this cyclist should obey the airlines request for deflation of the bicycle tyres before the flight.

At sea level, the maximum difference in pressure = 8 bar – 1 bar = 7 bar

At 10 000m above sea level, the difference in pressure = 5.69 bar – 0.28 bar = 5.41 bar

Since the difference in pressure is within the safety limit, there is no need for the cyclist to deflate the bicycle tyre.

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“INFLUENZA” OR INFLUENCER

By Mr Fung Jia Pei

The A-Levels have ended, and you and your friends are planning a graduation trip. How would you choose your holiday destinations or the hotels to stay at? In this social media age, it is not just competitive pricing and service that hotels focus on in their strategy to capture higher demand, but also advertising and branding.

Traditionally, the hotel industry would rely on big-budget advertising firms to do a one-off advertising campaign where the result may be uncertain. Now, many hotels are instead turning to multiple content creators, or social media influencers, who have specific audiences that the hotels may want to reach out to. Using the same budget, hotels now have a greater degree of certainty of success as globetrotting influencers such as @jacob, @gypsea_lust, and @worldwanderlust are able to invoke in their millions of followers the desire to emulate the same luxurious or hipstertravel lifestyle.

Hence, it is important for hotel owners and managers to be prudent in their choice of strategy as they navigate a complex mix of factors – not just this digital age in which consumers might have new tastes and preferences, but also this pandemic-era when governments have specific requirements on health and safety.

Assuming that you have been hired as a consultant for the hotel manager, what do you think are some factors that hotel owners should consider when deciding whether to engage the services of social media influencers?
What are some economic concepts that you’ve learnt this year that would help you answer this question?*

When making decisions, it is important to assume that hotel managers are rational, self-interested and insatiable economic agents. Based on these assumptions, hotel managers need to first consider their objective (which is typically assumed to be profit maximising) and constraints that they might face. For example, constraints include budget constraints as well as the availability of resources. Budget constraints are particularly important in this case as any financial reserves that the hotels might have are likely to be stretched due to the covid-19 pandemic.

Thereafter, rationality suggests that hotel owners would use the marginalist principle to make the decision on whether to hire social media influencers.

They would consider the potential additional revenues that the influencers might bring (marginal revenue), as well as the additional costs involved (marginal costs). But herein lies a problem.

It is very difficult for the hotel managers to acquire accurate information about the actual gains in revenue or rise in occupancy due to the hiring of social media influencers. More importantly they would also have consider the potential actions and reactions by their main competitors. If their rivals were to first adopt the strategy of engaging social media influencers, hotel owners might be left with no choice but to also adopt the same strategies. In light of this, there might be first-mover advantages enjoyed by the firm if it engages the services of influencers before its rivals.

Bearing in mind the potential problems of identifying the benefits and costs of such a strategy, hotel managers would decide to hire social media influencers only if the marginal benefits of doing so is more than (or at least equals to) the marginal costs.

The above economic analysis can be illustrated with the help of a diagram.
Try drawing the diagram yourself!

*Rational decision making process, market structure and reactions by rival firms.

Submit and win!
Q. Do you think that hiring social media influencers is the best strategy that hotel managers should adopt?
(In not more than 1,000 words, please explain your thoughts. Best answers will be showcased in next issue.)

Submit your answer to
[email protected]
and stand to win a Chicha Sanchen drink voucher*


Prizes are only for existing Learners’ Lodge student |  After the submission dateline, answer will be release to all who wrote in | 3 prizes to be won | 1 entry per student | Answers will be vetted by the author | Winner will be chosen based on the best answers deemed by the author | Submission dateline: 3 January 2023, 23:00 | Winner will be contacted after 04 January 2023

JC Magazine header 6

Airline over-booking

By Mr Teng Kah Seng

As the A’levels 2022 draws to an end, several of us, students and teachers will probably be going on overseas or cruise trips. In September, we saw an interesting news story where the Genting Dream passengers were turned away as the cruise company had overbooked. Before we look at how overbooking works, let us look at two different pricing strategies that operators use to maximize revenue.

The first will be yield management, where the purpose is to get the most revenue possible. An example of this will be the coach fares we pay and how the prices vary over time, for instance, early bird promotions. The second will be revenue management which considers data and optimizes the pricing and distribution in order to maximize the revenue. An example of this will be upselling, and also the topic today: Overbooking. Overbooking is very common and we can infer from the following excerpt.

“On Tuesday, the Consumers Association of Singapore (Case) president Melvin Yong told The Straits Times that it has received three complaints related to overbooking so far this year.”

What is overbooking?

It is a common practice for airline companies to sell more tickets for a particular flight than there are seats on the plane because customers who buy tickets do not always show up for the flight. Such a practice is called overbooking and is a strategy that airline and cruise companies use to protect themselves. Let us look at how companies use the binomial distribution to decide how many tickets they can overbook.


For a particular flight with 200 seats, a total of 205 tickets were sold.

Let X denote the number of no-shows for this flight.

Suppose that the probability of no-shows at flight time is 0.02.

We observe that X follows a binomial distribution with 205 trials with a probability of no-shows at 0.02. That is, X~B(205, 0.02).

Observe that we have a fixed number of trials here and a customer will either show up or not show up.

We must assume the following:

  1. The event that each customer does not show up is independent of the event that another customer does not show up.
  2. The probability of each customer not showing up is constant at 0.02.

Using this information, we can find the probability that the airline overbooked the flight. Since we have 205 tickets sold and only 200 seats available, let us illustrate some scenarios using the table below.

Chemistry Equation

Thus, the required probability will be given by 0.609. This implies that there is a 60.9% chance that the airline overbooks the flight.

Upon learning this, the manager is alarmed at the chance an overbooking can take place.

Submit and win!
Q. Can you find the number of tickets to be sold such that 90% of the time, the airline will not overbook its flight?

Submit your answer to
[email protected]
and stand to win a Chicha Sanchen drink voucher*


Prizes are only for existing Learners’ Lodge student |  After the submission dateline, answer will be release to all who wrote in | 3 prizes to be won | 1 entry per student | Answers will be vetted by the author | Only the correct answers will be entered into the draw | Submission dateline: 3 January 2023, 23:00 | Winner will be contacted after 04 January 2023

Auto, H. (2022). Overbooking by cruise operators and airlines: Consumer watchdog to engage STB, CAAS | The Straits Times. [online] www.straitstimes.com. Available at: https://www.straitstimes.com/singapore/consumer/consumer-watchdog-to-engage-stb-caas-on-overbooking-in-travel-industry [Accessed 30 Oct. 2022].

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GET TO KNOW OUR STAFF

Those of you attending classes at our Kembangan branch would be familiar with our friendly centre manager, Kristine. For our inaugural issue, we have interviewed Kristine to get to know her more beyond her welcoming demeanor!

Learners' Lodge staffQ: How long have you been a centre manager with Learners’ Lodge?

I’ve been a centre manager for over 4 years now. It’s been a fun-filled, memories-laden experience — indeed, time flies when you’re having fun!

Q: Could you share with us your philosophy as a centre manager?

I treat every interaction with any student or parent as an opportunity to learn something about them. Whether an interaction is long or short, I make it a point to be of help the best way I know how — and always with a smile. “Service” is very transactional. At the centre, I see those interactions as “growth & learning facilitations” because that’s essentially why we are here for students, parents, and teachers alike. I think we’re known as the centre with a conducive place for learning because we embrace that mindset.

Q: Many students probably only see you once a week and even when they do, they would only say hi before rushing into class, or say bye before rushing to go home. Can you describe your day as a centre manager for our students?

A regular weekend day starts at 8.10am. Although the first lesson starts at 9am, some students may arrive earlier and hence we will first spend time to sanitise the classrooms and all common areas to ensure that students are safe and protected at our centres. Especially now (due to COVID), we will also sanitise the classrooms after each lesson.

After sanitising the classrooms in the morning, we will then ensure the day-to-day operation is as seamless as possible so that teachers and students can have a smooth lesson. This includes calling students (and their parents) if they are not in class on time!

That being said, majority of the time spent at the centre is to maintain open lines of communication with students and parents. This involves registration of new students, arranging make-up lessons for students and addressing other concerns of parents. We would also regularly follow up with students or parents who have enquired about our lessons.

On weekends, our day ends at around 7pm after the last lesson ends.

Q: Centre managers are so busy on weekends! Could you share what you like to do on your off days or on days when the centre is not open?

Off days for me definitely means spending more time with family. Catching up with my young boys over meals we co-prepare is always something l look forward to. Occasionally, I go to the mall for some retail therapy—but almost always I end up buying something for my boys.

Q: Given your interactions with many graduating students over the years, are there any tips or advice that you’ll like to share with our JC1 students going to JC2 next year?

Consistency is key! How you prepare for your (A level) examinations will determine where you’ll land. But don’t forget to balance it out with a good amount of fun. If you’re feeling overwhelmed or if you have any concerns with your results, feel free to reach out to me at the centre!

Stay Updated

End of year is always the busiest time for administrative staff, teachers, and students at our centres. This year, especially, we have a lot more planned and a lot more to look forward to.

We wrapped up October with our #LLhalloween22 event, which we hoped had helped to relieve some exam stress for all of you. For those who participated, we hope you enjoyed the sweets and treats we have been dishing out! Let us take a look back at some of the highlights of the event:

JC Halloween Party

November and December are all about preparation, be it for A-levels or next year’s classes, preparation is always the key to staying on top of the game. Aside from our Head Start Programme, Topical Revision Workshop, and IP Bridging Programme, we also brought in external vendors to help all of you prepare for university interviews and, for those who are interested in the tech industry, a full Cloud-Computing bootcamp!

During the December break, some of the Learners’ Lodge centres will be having a brand new makeover as we adopt a brighter and fresher look. We are also introducing a new activity room that allows you to study and chill at our centre in the most conducive environment and a fully functional science lab for when you need to practise for your practical!

Moving on to 2023, we will be having our CNY event with all the Centres decorated in a festive mood and lots of gifts to be given out to our students! We hope all of you had a wonderful 2022 and we look forward to having you back at Learners’ Lodge next year!