Paper 3 SPM 2005 - Planning an Experiment

In paper 3 Chemistry SPM, a student is asked to plan an experiment based on the situation given. I have given this question to my students as an exercise. Most of the time, they would give me an wrong experiment plan. They planned experiment exactly the same as the experiment they carried out to investigate how the concentration of sodium thiosulphate affect its rate of reaction with sulphuric acid. 

Samples of answer please click here.

Aspirin

Aspirin is one example of analgesic which is normally used in treatment for headache and fever. However it is not suitable for kids as it can cause internal bleeding in the stomach.

Atomic Model

An atom consists of three types of subatomic particles:

• proton
• neutron
• electrons

Each subatomic particle have different properties. Students are advised to know their differences in terms of relative charge, relative mass and location in an atom.

In Paper 2 SPM 2006,  students are asked

• to compare the relative mass and the charge of two of the subatomic particles[4 marks].
• describe fully the atomic structure of lithium[6 marks].
• draw the structure of an atom of sodium or potassium[7 marks].

In Paper 2 SPM 2007, students are asked to

• describe and the atomic structure of hydrogen[4 marks].

Haber Process

Fritz Haber won the Nobel Prize in Chemistry in 1918 for synthesis of ammonia.

Haber Process from sweemoi khor

Read more about the

• Presentation  Speech
• Nobel Lecture

in the Nobel Prize Award Ceremony in 1920.

How to Determine Rate of Reaction

Rate Of Reaction from sweemoi khor

Vulcanization of Rubber

Charles Goodyear And Vulcanization from sweemoi khor

Latex

Rubber tree(Hevea brasiliensis) is quite common in Malaysia. The first rubber tree in Malaysia still can be found is in Kuala Kangsar, Perak. 

Latex is a white white milk-like fluid secreted by rubber tree.  It's a type of polymer, called polyisporene. Due to its elasticity, latex is widely used to produce latex glove, condoms and clothing.

Natural Rubber from sweemoi khor

Chemistry SPM Topic Links

Chemistry SPM Topic Links from sweemoi khor

This topic link of all topics of Chemistry SPM is prepared by Pn Wan Noor Afifah Wan Yusoff from SBPI Integrasi Gombak.

It showed the importance of few form 4 topics as basic to learn form 5 topics.

Kinetic Theory of Matter

   That's basic chemistry. But when I looked at my students' work in explaining kinetic theory of matter, thousands of questions popped up in my mind. How much do my students understand Kinetic Theory of Matter? It seems that it's such an abstract concept for them.  If I'm not mistaken, a student is exposed to this theory when they were studying Form 1 Science.

  Kinetic Theory of Matter explains that matter consists of tiny and discrete particles, which are always moving.
 
  Perhaps the theory is quite microscopic. We cannot feel it, see it or imagine it. But, there were some phenomena which can prove the Kinetic Theoryf of Matter. For example,

• Brownian movement.
• Diffusion in solid, liquid and gas.
• Changing of state of matter when heat is absorbed/released

  I'll post more how above examples can prove the Kinetic Theory of Matter.

When you sow an action, you reap a habit;

When you sow a habit, you reap a character;

When you sow a character, you reap a destiny.

A Perfect Graph

Graph Of Volume Of Gas Against Time

View more documents from sweemoi khor.

In the beginning of Chapter 1, Rate of Reaction in Form 5 Chemistry, a students needs to draw a graph to show the changes of quantity of reactants/products over a period time.

A perfect graph must have few criteria as follows:

1. Title
2. Label the two axes with the correct unit
3. Choose a suitable scale. The size of the graph should be at least ¾ of the size of the graph paper.
4. Plot all the points correctly
5. Smooth graph (curve or straight line )

   Most of the time, I found my students a bit hard to draw a perfect graph especially when drawing a smooth graph.  Perhaps they need a sharp pencil and more practice.  The skill again will be assessed in PEKA through the coming experiments to investigate the effect of temperate and concentration of reactants on the rate of reaction. All the best and good luck!!

Are Food Additives Good???

Food additives are added in a small quantitiy in food, mainly to

• make the food last longer
• add flavour
• enhance the food colour
• improve the food texture

There many types of food additives, as follows:

Type Of Food Additites

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Do all these food additives bring any harm to our health? It's a question to ponder.
For example, if food which is rich with salt might cause high blood pressure, heart attack and stroke. High intake of sugar cause diabetes, tooth decay and obesity. Some other food additives, as we explore more through this folio, we will realise their disadvantages.

Do our family members like to add lots of MSG into their mee? Does our little brother like to eat a lot of colourful sugar? Try to think few of your family member eating habits and advice them after you realise some disadvantages of food addtivies.

Red Cabbage Juice as An Acid Base Indicator

Have you ever tried this red cabbage(Brassica oleracea var. capitata f. rubra) before? It's often used for salads. Some of friends do not dare to tried even a small piece of it because of its colour.

The cabbage is red/purple, due to the presence of a colour pigment called anthocyanin. Its colour depends at the pH value of the soil. 

More acidic soil, the leaves grow more reddish.

More alkaline soil, more greenish yellow cabbage is produced.

Due to this special characteristic, red cabbage juice can be used as a home made acid base indicator. For more details, please visit http://www.funsci.com/fun3_en/acids/acids.htm.

Try to look around your garden too. May be you can colloect some flower petals and test whether there is any colour when difference acidic/alkaline substances are added. Who knows you might discover your own natural indicator too! Please don't forget to share with me your new finding too!!!

Predict the Product of Electrolysis of Aqueous Solution

Most students are having a big problem in electrochemistry.  Normally questions related to electrolysis of aqueous solution are their common mistakes.

This is one of the questions in Chemistry SPM 2009 Paper 2.

Electrolysis Of Potassium Iodide Solution from sweemoi khor

If you need guide to predict the product of electrolysis of aqueous solution, click here.

You're welcomed to email your answer to sweemoi@gmail.com.  I'll reply and give comments as soon as possible.

Rate of Reaction between Zinc and Hydrochloric Acid

This video shows the reaction between zinc and hydrochloric acid.  Hydrogen gas is released in both conic flasks.

Points to ponder:

1. Any possible reasons that contribute the different size of ballons in both experiments?
2. How to measure the of rate of reaction?