Boiling point of n-Butanol: details and influencing factors
n-Butanol, also known as 1-butanol, is a common organic compound widely used in the chemical, paint and pharmaceutical industries. The boiling point is a very critical parameter for the physical properties of n-Butanol, which not only affects the storage and use of n-Butanol, but also its application as a solvent or intermediate in chemical processes. In this paper, we will discuss in detail the specific value of n-butanol boiling point and the influencing factors behind it.
Basic data on the boiling point of n-butanol
The boiling point of n-butanol is 117.7°C at atmospheric pressure. This temperature indicates that n-butanol will change from a liquid to a gaseous state when heated to this temperature. n-Butanol is an organic solvent with a medium boiling point, which is higher than that of small molecule alcohols such as methanol and ethanol, but lower than that of alcohols with longer carbon chains such as pentanol. This value is very important in practical industrial operations, especially when it comes to processes such as distillation, separation and solvent recovery, where the exact value of the boiling point determines energy consumption and process selection.
Factors affecting the boiling point of n-butanol
Molecular structure
The boiling point of n-butanol is closely related to its molecular structure. n-Butanol is a linear saturated alcohol with the molecular formula C₄H₉OH. n-Butanol has a higher boiling point because of the stronger intermolecular forces (e.g., van der Waals forces and hydrogen bonding) between linear molecules compared to branched or cyclic structures. The presence of a hydroxyl group (-OH) in the n-butanol molecule, a polar functional group that can form hydrogen bonds with other molecules, further raises its boiling point.

Atmospheric Pressure Changes
The boiling point of n-butanol is also affected by atmospheric pressure. The n-butanol boiling point of 117.7°C refers to the boiling point at standard atmospheric pressure (101.3 kPa). Under lower atmospheric pressure conditions, such as in a vacuum distillation environment, the boiling point of n-butanol will decrease. For example, in a semi-vacuum environment it may boil at temperatures below 100°C. Therefore, the distillation and separation process of n-butanol can be effectively controlled by adjusting the ambient pressure in industrial production.

Purity and co-existing substances
The boiling point of n-butanol may also be affected by purity. High purity n-butanol has a stable boiling point of 117.7°C. However, if impurities are present in n-butanol, these may alter the actual boiling point of n-butanol through azeotropic effects or other physicochemical interactions. For example, when n-butanol is mixed with water or other organic solvents, the phenomenon of azeotropy may cause the boiling point of the mixture to be lower than that of pure n-butanol. Therefore, knowledge of the composition and nature of the mixture is essential for accurate boiling point control.

Applications of n-butanol boiling point in industry
In the chemical industry, the understanding and control of the boiling point of n-butanol is important for practical purposes. For example, in manufacturing processes where n-butanol needs to be separated from other components by distillation, the temperature must be precisely controlled to ensure efficient separation. In solvent recovery systems, the boiling point of n-butanol also determines the design of the recovery equipment and the efficiency of energy utilisation. The moderate boiling point of n-butanol has led to its use in many solvent and chemical reactions.
Understanding the boiling point of n-butanol is essential for its use in chemical applications. Knowledge of the boiling point of n-butanol provides a solid basis for process design and productivity improvements, both in laboratory research and in industrial production.