A relative density bottle, also known as a specific gravity bottle, is used to determine the density of a liquid directly. Here's a step-by-step guide on how to use it:
Steps to Use a Relative Density Bottle
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Weighing the Empty Bottle: Begin by carefully weighing the clean and dry relative density bottle. Note this mass down as m.
- Make sure the bottle is completely dry to get an accurate reading.
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Weighing the Bottle with the Liquid: Fill the bottle completely with the liquid whose density you wish to determine, ensuring there are no air bubbles. Weigh the filled bottle and note this mass as m1.
- The bottle should be filled up to the brim to ensure the same volume of the liquid.
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Weighing the Bottle with Water: Empty, clean, and dry the bottle thoroughly. Then, fill the bottle completely with water, ensuring no air bubbles. Weigh the filled bottle and note this mass as m2.
- Use distilled water to achieve the best results for the reference liquid.
Calculating Relative Density
After obtaining these three mass measurements, you can use the following formula to find the relative density of the liquid:
Relative Density = (m1 - m) / (m2 - m)
Where:
- m is the mass of the empty bottle.
- m1 is the mass of the bottle filled with the liquid.
- m2 is the mass of the bottle filled with water.
Example
Let's say:
- m (mass of empty bottle) = 20g
- m1 (mass of bottle with liquid) = 60g
- m2 (mass of bottle with water) = 50g
Then, the relative density of the liquid is calculated as:
Relative Density = (60 - 20) / (50 - 20) = 40 / 30 = 1.33
Therefore, the relative density of the liquid is 1.33
Summary of the Process
| Step | Description |
|---|---|
| 1. Weigh Empty | Weigh the clean and dry bottle. Record this as m. |
| 2. Fill & Weigh with Liquid | Fill the bottle with the liquid to be tested and weigh. Record this as m1. |
| 3. Empty & Refill with Water | Empty, dry and fill the bottle with water, weigh. Record this as m2. |
| 4. Calculate | Use the formula: (m1 - m) / (m2 - m) to determine the relative density. |
