How Does Pressure Increase the Rate of Cooking?

 The high temperature in pressure cooker increases the boiling point of  water to a temperature above 100 ⁰C.  The food absorbs more heat.  Hence, the time taken for the food to be cooked becomes shorter.  Thus the food is cooked  faster at a higher temperature in a pressure cooker.

Measurement of Rate of Reaction between an acid with Marble Chips

How to measure rate of reaction between an acid with marble chips?

First, we need to figure out the observable changes in quantity of reactant/product.

The observation mostly given by my class students are as follows :

1. marble chips dissapears.
2. gas bubbles produced.

Which quantity they would like to measure? Ha ha.. many students were stucked and were unable to given any response. Some might gave nonsence. The hand glove was purposely fixed on the mouth of a beaker filled with acid and marble chips. Soon, they realised it wasn't an accurate way of measurement the quantity of gas.   Slowly the students were guided to use the water displacement method to measure the changes in volume of gas released per unit time.

Chemistry SPM 2011

Paper 1

Paper 2

Paper 3

Answer for Paper 1 Chemistry SPM 2011

Courtesy from Mr Sai Mun Blog

Colourful Gemstones & Chemistry

Colourful gemstones, chemistry, transition element

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Aspartme

I guess many of us have seen this at the coffee shop.  It is an artificial sweeter which is 200 times sweeter than normal sugar we are taking.  Normally it is taken by people with diabetes. 

As we check at its ingredients, it consists of  phenylalanine. The labels "Phenylketonurics: Contains Phenylalanine" is necessary in any food consists of aspartame.  It must be avoided by people with phenylketonuria, a  genetic disorder in which the body lacks the enzyme necessary to metabolize phenylalanine. If not treated, the disorder can cause brain damage and progressive mental retardation. 

Molecular structure of aspartme

Cleansing Action of Soap

How Soap is Made?

1,000-year-old Tradition of Olive Oil Soap

Chic soap's ancient history by CNN_International

Biodegradable Oil Palm Waste Product

Being creative! Oil palm waste is turned to an useful paper product. Many types of brown cover notebooks on the shelves are biodegradable paper products. Not to surprised the product was invented in Malaysia.

More details, please read http://www.mysinchew.com/node/58773

Define Operationally Hardness of Alloy

Define operationally of hardness of alloy

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Target for Chemistry SPM

Define Operationally of Reactivity of Alkali Metals with Oxygen

Operational Definition of Reactivity of Alkali Metals with oxygen

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Form 4 SBP Year-End Examination 2011

Paper 1; Answer

Paper 2; Answer

Paper 3; Answer

Writing an Inference for Reaction involving Alkali Metal

Quick tip when giving inference. Ask yourself WHAT, HOW, WHY.

How does this solution formed?  White powder reacts with//dissolve in water.
Why does this solution turns red litmus paper to blue? The solution is alkaline.
What is that solution? It is potassium hydroxide.


Inference: Potassium oxide reacts with water produce potassium hydroxide which is an alkaline solution