The vapor pressure of HCl at room temperature is 4352 kPa at 21.1 °C.
Hydrogen chloride (HCl) is a highly volatile compound, meaning it readily transitions into a gaseous state, even at moderate temperatures. Its significant vapor pressure at room temperature indicates its nature as a gas under standard atmospheric conditions.
Understanding Vapor Pressure
Vapor pressure is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. For substances like HCl, which exist as a gas at room temperature and standard pressure, the "vapor pressure" often refers to the pressure of the gas itself, or the pressure at which it would condense into a liquid.
HCl Vapor Pressure Data
The specific vapor pressure for hydrogen chloride at a commonly accepted room temperature is detailed below:
| Property | Value |
|---|---|
| Vapor Pressure | 4352 kPa (at 21.1 °C) |
- Temperature Context: Room temperature is generally considered to range between 20 °C and 25 °C (68 °F and 77 °F). Therefore, 21.1 °C is a precise and representative measurement for the vapor pressure of HCl at typical room conditions.
- Pressure Units: 4352 kPa (kilopascals) is equivalent to approximately 43 atmospheres (atm) or 631 psi (pounds per square inch), highlighting that HCl is well above its critical pressure at this temperature, meaning it's a gas that would require very high pressure to liquefy without significant cooling.
Practical Implications of HCl's High Vapor Pressure
The high vapor pressure of HCl has several practical implications:
- Safety Concerns: Gaseous HCl is corrosive and can cause severe irritation to the respiratory system, eyes, and skin. Its high vapor pressure means that it can quickly fill a confined space if released, necessitating proper ventilation and personal protective equipment.
- Industrial Applications: Gaseous HCl is used in various industrial processes, including the production of vinyl chloride for PVC plastics, as well as in the pickling of steel to remove rust.
- Aqueous Solutions: When dissolved in water, HCl forms hydrochloric acid, a strong acid. The fuming observed from concentrated hydrochloric acid solutions is due to the escape of HCl gas into the air, which then condenses with atmospheric water vapor.
For more detailed information on hydrogen chloride, you can refer to its chemical properties and applications.
