How does density of a liquid affect the volume of its drop

Key Variables

Independent Variable

The densities of the liquid used:-

• •        Distilled Water- 1.00g/cm3
• •        Vegetable Oil- 0.91g/cm3
• •        Hydrochloric acid (2moldm-3)-1.19g/cm3
• •        Vinegar (Ethanoic acid)- 1.01/cm3
• •        Milk-1.03g/cm3

Dependent Variable

The volume of a drop

Controlled Variable

Volume of each liquid used (20cm3) 

Methodology

1. 1.        Gather all the apparatus.
2. 2.        Attach pipette pump to the glass pipette.
3. 3.        Extract 25cm3 of the liquid using the pipette pump and glass pipette.
4. 4.        Clamp the glass pipette onto the stand.
5. 5.        Drop the extracted liquid into the 25cm3 measuring cylinder until it’s full. (make sure to count the number of drops it takes to fill the measuring cylinder.
6. 6.        Record the data collected

    7. Use the following formula to calculate the volume of a drop of the specific liquid:

Volume of liquid in the cylinder

Number of drops

Safety Precautions:

• •        Wear safety goggles
• •        Do not ingest any of the liquids used in this experiment
• •        Make sure that the hydrochloric acid doesn’t come into contact with skin since it is corrosive.
• •        Handle the glassware carefully

Data Collection

Table 1: Number of drops of each liquid to fill 25 ml

Data Processing

Volume of liquid in the cylinder

Number of drops

Calculations

Milk: 25/480

=0.052 cm3

Vegetable Oil: 25/688

=0.036cm3

Vinegar: 25/508

= 0.049cm3

Distilled water: 25/426

= 0.058 cm3

Hydrochloric acid: 25/408

= 0.061 cm3

Table 2: The volume of a drop of liquid x and the density of liquid x

Graph 1: Graph of Density Vs. Volume of a Drop

Data Analysis

It can be seen that the volume of a drop does generally increase with the increasing density because the points rise from 0.036cm3 to 0.061cm3. However, there is a slight anomaly where the volume of the drop decreases and increases again rather than a smooth curve upwards. This is due to the errors made in the experiment

Conclusion

Although there were a few anomalies, my hypothesis proved to be correct because the volume of a drop did generally increase as the density increase. This is because the denser a liquid is, the more viscous it is therefore the volume of a droplet will be thicker than when the liquid is less dense, the droplet has less volume but due to surface tension it does not break into smaller droplets.  So in conclusion, my hypothesis that the higher the density the greater the volume of a drop of that liquid was correct

Evaluation