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

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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?

Relationship Between Concentration of Acid and pH Value

Chemistry SPM 2009 Paper 3 Q3 from sweemoi khor

This question appeared in Negeri Sembilan Trial paper. Those students from this state are very lucky.

Some students said they didn't carry out this experiment in their chemistry laboratory. Thus they have no idea how the experiment plan should be.

To my dear current form 4 students, Let's discuss this question together.

Common Chemicals

Common salt - sodium chloride
Table Sugar - sucrose
Vinegar - ethanoic acid
Vitamin C - ascorbic acid
Baking soda - sodium bicarbonate
Dry ice - solid carbon dioxide
Aluminium foil - aluminium
Copper wire - copper
Clean sand - silicon dioxide
Diamond - carbon crystal

SPM 2009 Paper 1, 2 & 3

Paper 2

1. Alloy
2. Period 2 & formation of ionic bond
3. Empirical formula of copper oxide
4. Homologous series, chemical properties of alkene
5. Rate of reaction, collison theory
6. Heat of neutralisation
7. Homologous series, empirical formula & molecular formula & isomerism
8. Electrochemical series based on potential difference, factor of concentration towards the producf of electrolysis of an aqueus solution
9. Redox reaction involving changing iron(III) ion to iron(II) ion, U tube
10. numerical problems involving molarity, role of water on the properties of acid, confirmatory test of cation and anion in a sample of salt given

Paper 3

1. Electrolytic cell: study how the type of electrode affect the product of electrolysis of copper(II) sulphate solution
2. Rate of reaction between marble chip and acid
3. Relationship between the concentration of acid and pH value.  A look at the question.

Paper 1
 
  I notice some blogs already uploaded with the answer. May be you all can have a look. Click here.

Chemistry Related Career

   One day, one of my students came to approach me after the end of her chemistry lesson.
    "Teacher, is it good I further study in chemistry?" She asked.

   "Of course, yes! But which part of chemistry do you like the most?" I said.

   She started to fall into a deep thought.

   Actually, deep in my heart, I'm glad my students have interest and plan to study more about chemistry.

  There are many fields requires chemistry knowledge:

1. food science
   
2. forensic science
3. environmental science
4. oceanology
5. geochemistry
   
6. education(teacher, or lecturer)
7. biotechnology
8. medicine
9. engineering
10. plastic chemistry
    
11. metallurgy
12. agrochemistry
13. pharmaceuticals
14. dietian

  The list is incomplete. Chemistry works in any industrial, educational, scientific, or governmental field. A chemistry student is equipped with excellent analytical and mathematical skills which help them to solve problems in their job.


  Perhaps I'll post more chemistry related career later. So, what's your choice?

 For further reading, you might visit American Chemical Society.

Medicines

Medicines

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What are Soap and Detergent?

Most of my students are wondering how to identify soap and detergents? In fact, it's not easy to identify through their physical properties.  Soap and detergent are different in term of their chemical structures and their chemicals required during preparation. Hopefully the slideshow below will help you to to have a better idea.

Soap and Detergents

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What's in your food?

I find this book particular interesting. The author, Chia Joo Suan who is a food chemist give us a closer look at food through comprehensive and easy-to- read guide.

Food is important. We consumer food not only to sustain our life but also for their taste, nutritional and medicinal values. Are the food we are taking safe? Many food additives are added to enhance food quality. Do we realize what are they? Do these food additives bring any side effects to our health in the long term?

Chemicals for Consumer

The discovery of chemicals manufactured for consumers such as cleaning agents, food additives and medicines has helped us improve our health and standard of living. Today, different type of these chemicals are produced to meet the needs and preferences of consumers. Therefore, understanding the chemistry of these chemicals will help a consumer select and use them wisely.

Hopefull this holiday assignment will make you realise the importance of many chemicals available in your daily life.  Any doubt, don't be hesitate to ask. Enjoy your holidays!