Density Lab Report Essay

DENSITY OF LIQUIDS AND SOLIDS

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Lab instructor:

Due date:

Results and discussion:
The purpose of the experiment was to determine the densities of the unknown liquid and solid as precisely and accurately as possible in order to identify them.
It was carried out first on distilled water in order to rule out systematic errors.
A 10 mL beaker was placed on a top pan balance and “tared”. The beaker was then removed and 10 mL of distilled water was pipetted into it before it was placed on the balance again. Thus, the mass of the water was obtained.
Five experimental trials were performed. The data and calculated results were tabulated (Table 1).
Table 1: Mass and Volume of Water and Density Calculations
Trial # Mass of water
(g) Volume of water (mL) Density of water (g/ mL )
1 9.95 10.00 0.995
2 9.98 10.00 0.998
3 9.95 10.00 0.995
4 9.95 10.00 0.995
5 9.93 10.00 0.993

The densities were calculated using the relationship
Density (g/ mL) = (Mass (g))/(Volume (mL))

An example of such a calculation using the trial #1 data:
Density (g/ mL) = (9.95 (g))/( 10.00 (mL)) = 0.995 g/mL

The average of these five determined density values,
(0.995 g/( mL) + 0.998 g/mL + 0.995 g/mL + 0.995 g/mL + 0.993 g/mL)/5 = 0.995 g/mL was considered to be the density of the distilled water.
Given the relatively small average deviation of the calculated density values,
(|0.995 g/( mL)-0.995 g/( mL)| +|0.998 g/mL- 0.995 g/( mL)|+|0.995 g/mL-0.995 g/( mL)| +|0.995 g/mL- |0.995 g/( mL)| +|0.993 g/mL- 0.995 g/( mL) |)/5
= 0.001 g/mL the results were determined to contain an adequate degree of precision.
Given the relatively small percentage error of the calculated density,
Error = 1 g/mL – 0.995 g/mL = 0.005 g/mL
Percentage error = (0.005 g/mL)/( 1 g/mL) * 100% = 0.5 % the results were determined to contain an adequate degree of accuracy.

Next, the experiment was carried out on Liquid 3. A 10 mL beaker was placed on a top pan balance and “tared”. The beaker was then removed and 10 mL of Liquid 3 was pipetted into it before it was placed on the balance again. Thus, the mass of the Liquid 3 was
obtained.
Five experimental trials were performed. The data and calculated results were tabulated (Table 2).
Table 2: Mass and Volume of Liquid 3 and Density Calculations
Trial # Mass of Liquid 3 (g) Volume of Liquid 3 (mL) Density of Liquid 3 (g/ mL )
1 7.99 10.00 0.799
2 7.96 10.00 0.796
3 8.00 10.00 0.800
4 7.99 10.00 0.799
5 8.00 10.00 0.800

The densities of Liquid 3 were calculated using the same method used to calculate the densities of distilled water. The average density of Liquid 3 was calculated using the same method used to calculate the average density of distilled water,
Average density = 0.799 g/mL and was considered to be the density of Liquid 3. The standard deviation of the densities of Liquid 3 was calculated using the same method used to calculate the standard deviation of the densities of distilled water. Given the relatively small average deviation of the calculated density values,
Standard deviation = 0.001 g/mL the results were determined to contain an adequate degree of precision.

Using the table provided, it was concluded that the identity of Liquid 3 was Ethanol, 96%.

The error and percentage error of the calculated value of the density of Liquid 3 were calculated using the same method used to calculate the error and percentage error of the calculated value of the density of distilled water. Given the relatively small percentage error of the calculated density,
Error = 1 g/mL – 0.995 g/mL = 0.005 g/mL
Percentage error = (0.005 g/mL)/( 1 g/mL) * 100% = 0.5 % the results were determined to contain an adequate degree of accuracy.