19th August 2010

3) (i) Today I learnt that factories make use of the fractionating column to separate crude oil into its simpler hydrocarbons. In order for separation to occur, the substances must have different boiling points.

Process:

- The crude oil is first burned in the furnace.

- The substances that have the lowest melting point and is the lightest will travel to the top of the column.

- The substances with the highest melting point pand is the heaviest will travel to the bottom of the column.

- The substances at the top are in gaseous state while the ones in the centre are in liquid state and the ones in the bottom are in solid-liquid state.

- more complex substances are found at the bottom while

less complex substances are found at the top.

(ii) Today we also went through of how the distillation set-up works.

process:

- The mixture is first heated in a beaker.

- The water evaporates into vapour.

- The vapour condenses in the condenser

- The water droplets flows down the condenser and into the conical flask

-If the temperature on the thermometer increases, it means that you are no longer collecting water.

(iii) Today we also compared some of the differences between fractional distillation and distillation

Some of the points are:

- Fractional distillation separates more than one substances while distillation separates two substances.

- Fractional distillation makes use of a fractionating column while distillation makes use of a Liebig condenser.

- Fractional distillation is used in factories while distillation is used in labs

2) (i) What other substances besides crude oil can be separated using fractional distillation?

(ii) How does the substances in the fractionating column stay in their corresponding segments?

1) I can apply what I learnt today when I need to separate a mixture of two iquids using distillation.

16th August 2010

3) (i) After todays practical experiment, I know how to separate solutions using the method distillation. Mdm Riza showed us experiment on distillation.
The apparatus needed were:
-bunsen burner
-tripod stand
-beaker
-solution of syrup amd water
-conical flask
-condenser
-thermometer
steps:
- The water first boils from the mixture in the beaker and then then turns into a gaseous state after being heated.
- The water vapour then condenses in the condenser.
- It flows down the condenser and then into the conical flask.
(ii) Chromatography is used to separate coloured substances like ink or dye. We conducted an experiment on chromatography by ourselves today.
The apparatus needed were:
- chromatography paper
- test tube holder
- test tube
- solvent
- ink
- cork
-pencil
steps:
- Draw a horizontal line across the breadth of the chromatography paper about 3 cm from the bottom.
- Fill the test tube with a height of 2 cm of solvent
- Place the chromatography paper into the tast tube
- Cover the test tube with the cork
- Place the test tube on the test tube holder and wait for the colour of the ink to change.
(iii) During todays experiment, we used the learning method of predicting, observing and explaining. I think this is a good learning technique as it can let us think of what the topic is before going deeper in depth.
2) (i) Is the syrup left in the beaker after it boils?
(ii) Can we use other types of paper besides chromatography paper to carry out the experiment?
1) Distillation can be used when we don,t have water with us besides sea water to obtain pure water.