The purpose of this experiment was to examine physical properties such as density and boiling point. This is to determine the identity of an unknown substance using several instruments for measurement. (Xidos, 2013-2014)
The unknown liquid code received, was L83. I observed that it had a very strong odour and appeared a transparent colour in the beaker.
Procedure A. Determination of the density of the unknown liquid.
The unknown liquid code received, was L83. I observed that it had a very strong odour and appeared a clear in the beaker.
Each method was completed a total of three trials.
Density = Mass divided by Volume (Xidos, 2013-2014)
Method 1. Graduated Cylinder 50ml
Unknown substance was measured at 15ml, 30 ml, and 45 ml, their mass recorded on a balance in a 50 ml graduated cylinder.
The average density: = 0.800+ 0.0800+ 0.680 = 2.280
=2.280/3 = 0.76 g/ml
Method 2. Volumetric Pipette 10 ml
Unknown liquid was measured in a 150 ml beaker. Using a volumetric pipette to measure 10 ml, 20 ml, 30 ml respectively.
The average density: =0.750+ 0.727+ 0.720 = 2.197
= 2.197/3 = 0.73 g/ml
Method 3. Burette
Unknown liquid was measured into a 150 ml beaker and using a burette to measure 13 ml, 26 ml, and 39 ml of the liquid and recorded masses.
The average density: =0.82+ 0.77+ 0.77 = 2.36
= 2.36/3= 0.79 g/ml
Note that the burette was the most accurate in determining accuracy of measured amounts.
The average density for all three of these methods is: = 0.76+ 0.73+ 0.79 = 2.28
=2.28/3= 0.76 g/ml
Procedure B. Determination of the boiling point of an unknown liquid
Note that the atmospheric pressure in the lab room is 100 Kpa. (Xidos, 2013-2014)
Required: An assembled boiling point apparatus. Fifteen drops of the unknown liquid was then placed into an empty test tube. Apparatus was used to heat up test tube in a water bath. Placed in heated beaker was a...