What is the specific gravity, Flash Point and Flammability Range of Acetone?
The correct answer and explanation is:
Correct Answer:
- Specific Gravity of Acetone: 0.79 (at 20°C relative to water)
- Flash Point of Acetone: −20°C (−4°F)
- Flammability Range (in air): 2.6% to 12.8% by volume
300-Word Explanation:
Acetone, also known as propanone, is a highly flammable, volatile, and colorless liquid commonly used as a solvent in industries and households.
1. Specific Gravity (0.79):
Specific gravity is the ratio of the density of a substance to the density of water at a specific temperature (usually 4°C or 20°C). Acetone’s specific gravity is 0.79, which means it is lighter than water. If poured into water, acetone would float on top. This low density is a result of its small molecular structure and relatively weak intermolecular forces compared to water.
2. Flash Point (−20°C):
The flash point is the lowest temperature at which a liquid can form a vapor that ignites in air when exposed to an ignition source. Acetone has a very low flash point of −20°C (−4°F). This makes it extremely flammable even at room temperature or below. That’s why acetone must be stored in well-ventilated areas, away from open flames or sparks.
3. Flammability Range (2.6% to 12.8%):
The flammability range indicates the concentration of acetone vapor in air within which it can ignite. For acetone, this range is between 2.6% (lower explosive limit) and 12.8% (upper explosive limit) by volume. Below 2.6%, the mixture is too lean to burn; above 12.8%, it is too rich. This wide flammable range makes acetone hazardous in confined spaces where vapors can accumulate.
Conclusion:
Acetone’s low specific gravity, low flash point, and broad flammability range make it a useful but potentially dangerous solvent. Proper ventilation, storage, and handling procedures are critical to ensure safety when using acetone in labs, industries, or homes.