Merely Tips 1

This post is my reply to Tanuja who asked me how I studied for both Chemistry and Biology.

To tell the truth, everything requires practice. The tips I used to remember the facts are not to MEMORISE. This is because, memorising will only make you rigid and unable to adapt when you are tensed. So the best way that I did was to visualise the facts and process while reading and try to at least do some 'process diagram' to show the flow and jot down some important keywords on the picture. As you read be sure to understand the facts and the flow, don't just read to memorise but read to understand. Through understanding, you'll be able to familiarise.

Take for example: Antagonistic movement of the arm. Since the arm is with you even in exams, you'll be able to cheat. Not the literal meaning of cheat but to take it as a guide. When you put your arm in a bend position (the showing muscle pose), you can feel and see that the biceps (upper muscle) is tensed. This means that it is contracted. Antagonistic movement has opposite characteristics between the two muscles involved so automatically when biceps contracts, triceps relaxes (during hand bending); during hand straightened, the biceps relaxes while the triceps contracts. See how easy it turned out to be? That's why you're given hints by your body.

If the topic is not related to your body, like plants. You have to visualise the existance of them when you are part of them. It will be much easier to remember if you are doing the thing as in you try to use more senses. The more senses you involve the more percentage the knowledge can be absorbed (research had shown). So it will be best you can read aloud as you try to understand the facts ;)

Chemistry, it's more to understanding the basic concept before applying the real thing. You'll have to be able to remember basic chemical reaction for you to be able to write the equation, apply into the experiment and the further calculation.

Let's take for example the preparation of salts. The basic concept here is that you'll have to know what are the salts to be produced. If it is a soluble salt is it a special (ammonium, sodium or potassium) salt? Or is it an ordinary salt? If it is a special salt, you'll have to use titration. Titration is the neutralisation reaction between an acid and an alkali. So you'll be able to predict what substances to be used.

Example 1: Soluble salt - Sodium Chloride
Since it is a soluble salt, and it is a special salt, titration is used. The ions involved in this case is sodium ion and chloride ion. Since an acid and an alkali is required, you can use sodium hydroxide solution and hydrochloric acid which contains the same ions as the salt you want to make.

Example 2: Soluble salt - Copper (II) sulphate
It is a soluble salt but not a special salt. From that you have to choose one between three other methods in preparing soluble salts.

1. Metal + acid -----> salt + hydrogen gas (reactive metal only)
2. Metal Oxide + acid -----> salt + water
3. Metal Carbonate + acid -----> salt, water, carbon dioxide

Note that copper ion is situated below hydrogen ion in the electrochemical series so it is not a reactive metal. Hence, method 1 cannot be used. Method 2 and 3 can be used because copper (II) oxide and copper (II) carbonate are salts that can react with acid. The product is also separatable from the solution as it contains only water or carbon dioxide which can be easily eliminated to get the salt crystals. So you can use copper (II) oxide or copper (II) carbonate with sulphuric acid to produce the salt.

Example 3: Insoluble salt - Barium Sulphate
It is insoluble so it only left the double decomposition/ precipitation reaction. That is to used two soluble salts which contains the ions needed like barium nitrate and sodium sulphate.

* You'll need to remember the salts which are soluble and insoluble. That's the thing you can't avoid.