The density of liquid butane is 720.9 g/L (or 720.9 kg/m³) when measured at a temperature of 150 Kelvin. Butane's density, like that of most substances, varies significantly with temperature and pressure.
Understanding Butane Density
Butane (n-butane) is a versatile hydrocarbon widely used as a fuel, refrigerant, and chemical feedstock. Its physical state and, consequently, its density are heavily influenced by environmental conditions, particularly temperature and pressure. In its liquid form, butane is significantly denser than in its gaseous state, a key property utilized in its storage and transport.
Specific Density Values
While density changes with conditions, a specific measurement provides a clear reference point. For liquid butane, a recorded density at a particular temperature is:
| State | Temperature [K] | Density [g/L] (kg/m³) |
|---|---|---|
| Liquid | 150 | 720.9 |
This table illustrates that at 150 Kelvin, liquid butane has a density of 720.9 grams per liter. This value highlights the compact nature of butane when it is in its liquid phase at very low temperatures.
Why Temperature Matters for Butane Density
Temperature plays a crucial role in determining the density of liquid butane due to the following reasons:
- Thermal Expansion: As temperature increases, the molecules in liquid butane gain kinetic energy, causing them to move further apart. This leads to an expansion in volume and a corresponding decrease in density, assuming a constant mass.
- Phase Transition: Butane transitions from a liquid to a gas at its boiling point, which is approximately -0.5 °C (31 °F) at atmospheric pressure. Above this temperature, butane exists predominantly as a gas, exhibiting a much lower density than its liquid form.
- Practical Implications: Understanding this temperature dependency is vital for the safe storage, accurate measurement, and efficient use of butane. For instance, a container filled with liquid butane at a lower temperature will hold more mass than one filled at a higher temperature, even if the occupied volume appears the same.
Practical Applications of Butane Density Knowledge
Knowing the density of liquid butane is essential in various industrial and commercial applications, ensuring precision and safety:
- Fuel Storage and Transport:
- LPG (Liquefied Petroleum Gas) Blends: Butane is often blended with propane in LPG. Density calculations help determine the precise composition, energy content, and volume-to-mass conversions of these blends.
- Tank Capacity and Filling: Accurate density figures are critical for designing storage tanks and transport vessels, ensuring they can safely contain a specific mass of liquid butane without overfilling, especially considering thermal expansion.
- Chemical Manufacturing:
- Feedstock Metering: In chemical processes where butane is used as a raw material, precise density data allows for accurate metering and control of reactants, ensuring optimal reaction conditions and product yield.
- Refrigeration Systems:
- Butane's thermodynamic properties, including its density, are considered when it's used as a refrigerant, particularly in specific low-temperature applications requiring efficient heat transfer.
- Consumer Products:
- Aerosols: Butane acts as a propellant in many aerosol products. Its density influences the formulation, spray pressure, and overall performance of the product.
- Lighters: The amount of butane in a lighter is often determined by volume. Understanding its density is crucial for manufacturers to ensure consistent fill levels and operational duration.
By accurately understanding the density of liquid butane at various conditions, industries can optimize processes, manage resources effectively, and enhance safety across a wide range of applications.
