lab report : physical properties

Physical Properties
Objective:
The main objective of this experiment is to find the unknown/given sample physical properties namely boiling point, melting point and refractive index using serious of experiments. The finding of physical property is first and foremost step in chemist world to find the unknown sample/molecule properties and its method been used for several centuries in chemist fields even today as a base for analysis. In melting point experiment, we will be using maleic acid and benzamide whose melting point are same in both molecules but it shows great variance on mixing each molecule which signifies each act as impurity for one another to show deviation in melting point. In boiling point experiment capillary based system is used to perform rise of liquid to get approx. value of temperature and acetone will be used as sample to find out the boiling point range since it is highly volatile by nature hence water-based heating is used instead of oil since boiling point of acetone is less than 95 C. The same unknown sample will from boiling point experiment will be used for experimental computing of refractive index, for this experiment Abbe-Spencer refractometer is used for analysis and water used as reference point since it has lowest refractive index.
Melting Point
Procedure:
A. Using a Thiele-Dennis tube
1. The given unknown sample is weighed and filled in capillary tube by tapping the open end of the tube into the sample. Invert the capillary tube and tap it on the bench top until the sample falls to the bottom of the tube, kindly note the sample height in capillary tube need to be in the range of 1/8 to ¼ inch. As out of this range height gives broader range of melting point difference for the sample.
2. The sample filled capillary tube is attached to the thermometer with rubber band and suspended in oil bath of Dennis-Thiele tube. (Note: rubber band should be kept out oil level)
3. The oil bath will be rapidly heated until it is about 20 C below the suspected melting point of the sample. Then the rate of heating is decreased and temperature of oil is steadily increased at the rate of 1-2 C per minute till reaching the sample melting point.
4. The temperature at which the formation of liquid layer in sample is observed and noted, then record the temperature at which the complete sample gets converted to liquid state as these two temperatures gives us melting point range.
5. The melting point for the sample is observed in the form of pure and mixture compounds as below
i. Benzamide
ii. Maleic acid
iii. Maleic acid: Benzamide (75:25)
iv. Maleic acid: Benzamide (50:50)
v. Maleic acid: Benzamide (25:75)
6. The data is observed/recorded and...