The Correct Use of a Microscope
In observation of samples
Practical No 2
Applied Biology and Chemistry
Title: The correct use of the microscope in observing a sample of (a) salt
and (b) pepper.
a) Determine the type of structure each sample have using the three magnifications on a compound microscope.
b) Identify each sample by using drawings and observations at all magnifications
The aim of this experiment is to put into practice the use of slides and the different types of samples which will be dealt with in the laboratory. Observing what is seen at different magnifications and reporting on the relevant information.
* Compound Microscope
* Observation notebook
* Lens tissue
* Set up the compound microscope as per laboratory manual.
* A sample (pinch) of (a) salt in placed on a clean dry slide.
* The sample is then observed with the objectives lens' at
* 4 x (40)
* 10 x (100)
* 40 x (400)
* 100 x (1000) magnifications
* Record the observations using diagrams.
* Repeat steps 1-4 for the sample of (b) pepper.
Table of Observational Results
Magnification | Salt | Pepper |
4x(40) | Square Crystaline appearanceTranslucentNo visible colourAgrigation of salt Sodiumhexacyanoferrate II . | Irregular shapeSome translucencyAmber, red ,brown colour |
10x(100) | Visibly similar | Visibly similar |
40x(400) | Cuboid Shape more distinguishable. | Irregular 3D shape |
100x1000) | No result | No result |
Salt Molecule :
(Refer to Fig 2.)
In NaCL, one atom loses an electron, the other gains an electron.
The removal of this electron from Na (sodium) gives a very stable electronic configuration.
Cloride (CL) on the other hand requires an extra electron to give it the same stable status as Na(sodium). The structure of this bond...