Sec 4 Combined Chemistry
Issues faced by Sec 4 students
Concepts are more in-depth and require an excellent understanding of the subject matter in order to solve many of the application questions. Students also often miss out on crucial keywords in their answering techniques, leading to significant loss of marks due to unfamiliarity with the marking scheme. ‘O’ Level questions are of a much higher difficulty level than normal practice questions and students are often unprepared for the gap-up in complexity.
Students are also often careless when attempting MCQ questions and get tricked by common pitfalls placed by examiners to trap them when they do not have a firm grasp of the foundational concepts. They also exhibit poor time management, leading to insufficient time to complete the examination.
Chemists like Humphry Davy and Svante Arrhenius played important roles in providing a comprehensive understanding of what happens in chemical reactions. A new era of electrochemistry started when Humphry Davy (1778–1829), a British chemist, built a powerful battery to pass electricity through molten salts. He discovered elements, such as potassium, sodium, calcium and magnesium, by liberating them from their molten compounds. Swedish chemist, Svante Arrhenius, in 1887, proposed the theory that acids, bases, and salts in water are composed of ions. He also proposed a simple yet beautiful model of neutralisation – the combination of hydrogen and hydroxyl ions to form water.
In this section, students examine the chemical decomposition of substances by electrolysis, characteristic properties, the factors affecting the rate of reaction and the energy changes during a reaction. Students should be able to appreciate the importance of proper laboratory techniques and precise calculations for accurate results, and the importance of controlling variables in making comparisons. They should also value the knowledge of the hazardous nature of acids/alkalis and the safe handling, storing and disposing of chemicals.
2. Energy Change
3. Speed of Reaction
Our atmosphere has been taken for granted in the past. In the last few decades, scientists and the general public began to realise the adverse effects of pollutants on the air we breathe. It is recognised that pollutants such as sulfur dioxide, oxides of nitrogen, carbon monoxide and particulates released into the atmosphere as a result of energy generation and increased use of motor vehicles, have serious health and environmental consequences.
In this section, the sources of air pollutants and their effects are examined. Students should be able to value the knowledge of the hazardous nature of pollutants and the environmental issues related to air pollution.
4. Air and Atmosphere
In the nineteenth century, chemists believed that all organic chemicals originated in tissues of living organisms. Friedrich Wohler, in 1828, challenged this belief and synthesised the organic compound urea, a compound found in urine, under laboratory conditions. His work led other chemists to attempt the synthesis of other organic compounds.
In this section, students examine the sources of fuels, some basic concepts of organic chemistry such as homologous series, functional group, general formula and structural formula, and polymers. Students should be able to identify and name unbranched alkanes, alkenes, alcohols and carboxylic acids. They should recognise that materials such as plastics, detergents and medicines, and even the food that we eat are examples of organic compounds. Students should be able to value the need for assessing the impacts of the use of synthetic materials and the environmental issues related to the use of plastics.
5. Organic Chem – Fuels and Crude oil
6. Organic Chem – Alkanes
7. Organic Chem – Alkenes
8. Organic Chem – Alcohol & Carboxylic Acids
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How are lessons like?
Lessons are fun, engaging and inspiring. Misconceptions that have eluded you will be debunked; tips and tricks will be shared. Minimise your memory work, experience a quantum jump in your level of understanding, and most importantly, go home feeling satisfied and tons smarter. No one gets lost here.
We will follow up with a tutorial session to close the chapter. Tutorials are crucial in linking up theory and application. We will first look at worked examples to give you ideas on how to approach a question.
Do you offer online lessons?
We are redefining how Chemistry tuition lessons should be taught. Instead of simply seeing your child once a week for 2 hours, we endeavor to provide greater support for your child’s learning through closer guidance 2-3 times a week at no additional charge!
Adaptation and flexibility is the essence as we navigate through this new era of learning. In order to help your child more effectively, we are employing a 3-pronged approach:
- 1) Online content lessons (these are recorded as well to allow students to watch at this own time and pace)
- 2) Online consults
- 3) Physical consults
For students who prefer a more traditional approach, we have sessions with physical teaching as well.
What happens if I cannot make it for a lesson?
Video-recorded lessons are also available for viewing for students who miss the entire week of lessons.
What happens if I join the class late and need help for topics that have already been covered?
We always have new students coming in who may need help for previously-taught chapters.
You can choose from either of the following:
- You may purchase our Chemistry Masterclass videos at a discounted rate, followed by a consultation session to clarify any questions that you may have.
- We will run crash courses every school holiday to readdress all the major chapters that were previously taught. You may want to attend the crash courses during the March, June and September school holidays to catch up on previously-taught chapters.