Finding the Identity of an Unknown Liquid

Purpose

The purpose to this experiment was to determine the identity of an unknown liquid. In order to do this, physical properties of this liquid were used. These properties include Density, boiling point, colour and even smell.

Results

Table 1

Determining the density of an unknown liquid using a graduated cylinder

Trial 1 Trial 2 Trial 3

Volume of Liquid (mL) 15.0 30.0 45.0

Mass of cylinder (g) 73.21

Mass of cylinder + Liquid (g) 85.81 97.82 109.85

Mass of Liquid (g) 12.60 24.61 36.64

Density of Liquid (g/mL) 0.8 0.8 0.8

In determining the density of the unknown liquid, 3 trials were done as shown in table 1 above. To calculate the Density, the formula:

Density = Mass/Volume

Trial 1: Density = 12.60 g/15.0mL=0.80g/mL

Trial 2: Density = 24.61 g/30.0mL=0.80g/mL

Trial 3: Density = 36.64 g/45.0mL=0.80g/mL

To get the average density, all the values from the three trials were added and divided by 3.

(0.80+0.80+0.80)g/mL /3 = 0.80g/mL

The density of the unknown liquid was also determined graphically as follows:

From the graph, the density of the unknown liquid can be determined by calculating the slope.

The slope a graph is rise/run

i.e (36.64g-12.60g)/(45.0g/mL-15.0g/mL)

24.04g/30.0g/mL =0.80g/mL

Table 2

Determining the density of an unknown liquid using a volumetric pipette

Trial 1 Trial 2 Trial 3

Volume of Liquid (mL) 10.01 20.02 30.01

Mass of empty beaker (g) 65.17

Mass of beaker + Liquid (g) 73.14 81.05 88.98

Mass of Liquid (g) 7.97 15.88 23.81

Density of Liquid (g/mL) 0.80 0.79 0.79

The average density of the unknown liquid using a volumetric pipette was found to be;

(0.80+0.79+0.79)g/mL/3

2.38g/mL/3 = 0.79g/mL

Graphically, the following result was arrived at:

From the graph, the density of the unknown liquid is:

Rise/Run

(23.81-7.97)g/(30.01-10.01)g/mL

= 0.79g/mL

Table 3

Determining the density of an unknown liquid using a burette

Trial 1 Trial 2 Trial 3

Initial burette...