Specific Gravity is defined as the ratio of weight/mass of a given volume of solids to the weight/mass of an equal volume of water at what temperature?

Specific Gravity is defined as the ratio of weight/mass of a given volume of solids to the weight/mass of an equal volume of water at what temperature?

• A. 0°C
• B. 4°C
• C. 20°C
• D. 100°C

Answer: (B)

Specific gravity is a ratio that compares how dense a solid is to the density of water, using a standard reference for water. Since water’s density changes with temperature, a fixed reference temperature is needed so SG numbers are comparable. Water is most dense at about 4 °C, with a density very close to 1.0 g/cm^3. By using water at this temperature as the reference, the SG value becomes a stable, convenient baseline. That’s why, in practice, specific gravity is defined using water at 4 °C—the denominator is essentially 1.0, so the SG value closely mirrors the solid’s density in g/cm^3. Using different temperatures would change the water density and thus shift the SG for the same material.

Specific gravity is a ratio that compares how dense a solid is to the density of water, using a standard reference for water. Since water’s density changes with temperature, a fixed reference temperature is needed so SG numbers are comparable. Water is most dense at about 4 °C, with a density very close to 1.0 g/cm^3. By using water at this temperature as the reference, the SG value becomes a stable, convenient baseline. That’s why, in practice, specific gravity is defined using water at 4 °C—the denominator is essentially 1.0, so the SG value closely mirrors the solid’s density in g/cm^3. Using different temperatures would change the water density and thus shift the SG for the same material.