You can calculate density from specific gravity by using a simple multiplication.
Specific gravity is a dimensionless quantity defined as the ratio of a substance's density to the density of a reference substance, usually water at a specific temperature (often 4°C). To find the actual density of a substance, you need to reverse this relationship.
Here's how to do it:
The core concept is that:
Density of substance = Specific Gravity × Density of Water
Steps to calculate density:
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Identify the Specific Gravity: Obtain the specific gravity of the substance you are interested in. This value is often found in material property tables.
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Determine Density of Water: Identify the density of water at the reference temperature used to measure the specific gravity. Typically, the reference temperature is 4°C where water has a density of approximately 1000 kg/m³ or 1 g/cm³. If the specific gravity is based on water at another temperature (such as 20°C or 25°C), use the corresponding water density for that temperature.
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Multiply: Multiply the specific gravity by the density of water at the appropriate temperature. The result will be the density of the substance in the same units as used for the density of water.
- For example, if you use 1000 kg/m³ for the density of water, your result for the substance's density will be in kg/m³. If you used 1 g/cm³, the result will be in g/cm³.
Example Calculation
Let's calculate the density of a substance with a specific gravity of 2.5, assuming the reference temperature for specific gravity was based on water at 4°C (density of water = 1000 kg/m³):
- Specific Gravity of Substance: 2.5
- Density of Water (at 4°C): 1000 kg/m³
- Density of Substance = 2.5 * 1000 kg/m³ = 2500 kg/m³
In summary, as mentioned in our reference, The Density of a substance may be calculated by multiplying the Specific Gravity by the Density of water at the reference temperature. This process is crucial in various fields such as materials science, engineering, and chemistry.
