(N01) Experimental Chemistry

Things to note for (N01) Experimental Chemistry:

Test tube & Boiling tube:

1. Vol. of a test tube = 20 ml (approx.)
2. Vol. of a boiling tube = 50 ml (approx.)
3. Test tube and boiling tube should not be used for measuring volumes of liquids. They can be used to contain liquids. However, do take note of their capacity to avoid transferring too much liquid into them. 
4. When heating substances in a test tube/ boiling tube, avoid filling it to more than half of its height, unless otherwise stated. 

Measuring cylinder:

1. Accuracy: +/- 1 ml (Example: 11 ml, 12 ml, 13 ml)
2. Refer to (P01A), when finding average volume of test tube and boiling tube: If the average reading is 22.3 ml, round it down to 22 ml. If the average reading is 55.6 ml, round it up to 56 ml. This is because we are using a measuring cylinder to measure the volume of the test tube and boiling tube. And the accuracy of the measuring cylinder is only +/- 1 ml.

Burette and Pipette:

1. Accuracy of burette: +/- 0.1 ml (Example: 0.0 ml, 11.1 ml, 12.4 ml, 13.9 ml)
2. Accuracy of pipette: 1 d.p (Example 20.0 ml, 15.0 ml, 10.0 ml)

Stopwatch:

1. Record to the nearest second.

Electronic weighing balance:

1. Accuracy of burette: 2 d.p (Example 7.67 g, 5.00 g)

Recording observations:

1. Always state the physical state of the substance (solid/liquid/gas).
2. Always state the colour of the substance.
3. When identifying the colour of a very pale solution, focus on the meniscus. The colour at the meniscus will indicate the colour of the solution.  

------------------------  Self-check: Can you perform the following? -----------------------

(P01A) Laboratory Apparatus Part I

1. Reading the volume of the liquid in a measuring cylinder?
2. Transferring of liquids and solids safely?
3. Reading the temperature shown on the thermometer?
4. Recording time taken?
5. Recording observations?

(P01B) Laboratory Apparatus Part II

1. Filling a burette with the use of a filter funnel?
2. Filling a pipette using a pipette filler?
3. Identifying the solution to be added to the burette and pipette?
4. Identifying the end-point of the reaction?
5. Recording of liquid level as shown in the burette?

(P01C) Crystallisation

1. Folding a filter paper?
2. Carry out filtration of a suspension?
3. Evaporating a solution?
4. Lighting a Bunsen burner?
5. Recording observation? 
6. Identifying the filtrate and residue?

(P01D) Chromatography

1. Transferring liquids safely?
2. Identifying the solvent to be used based on the procedure?
3. Calculating Retention factor for the different components?

-------------------------------------------- VIDEOS ------------------------------------------------

Video 1: Separating iron and sand mixture using a MAGNET.