An Insight into the Boiling Point of Ethanoic Acid

What is the boiling point of ethanoic acid? The ethanoic acid boiling point is 118.1 degrees Celsius. This means that the compound will vaporize at this temperature, turning from a liquid to a gas. The temperature at which the vapor pressure of ethanoic acid is equal to the standard atmospheric pressure. Here are the things that can change ethanoic acid's boiling point .

How Solvent Pressure Affects the Boiling Point of Ethanoic Acid

In general, when a solute is added to a solvent, the boiling point of the solvent will decrease. Ethanoic acid itself is technically considered a solvent since it dissolves many other chemicals. So adding ethanoic acid to water or any other liquids would be expected to lower the temperature at which the vapor pressure of ethanoic acid and that liquid are equal. Ethanoic acid will also dissolve in other acids like hydrochloric acid and sulfuric acid, lowering the boiling point.

Temperature

The higher the temperature of a liquid, the higher the vapor pressure. This means that the hotter liquids will have a higher vapor pressure at a given pressure than colder liquids. In general, increasing the temperature will increase the vapor pressure and therefore raise the boiling point. Ethanolic acid has a higher boiling point at higher altitudes since the atmospheric pressure is lower.

Intermolecular Forces

The boiling point of a liquid is also determined by the strength of the intermolecular forces between the molecules. The stronger the forces, the higher the boiling point. Ethanoic acid has very weak intermolecular forces, and so has a relatively low boiling point. Adding other compounds that have stronger intermolecular forces, like water, will raise the boiling point. Intermolecular forces are also the reason why ethanoic acid will dissolve in other liquids. The more intermolecular forces between ethanoic acid and another liquid, the more soluble it can be.

Change of State

Since the boiling point is related to vapor pressure, then changing states would change the boiling point as well. For example, boiling ethanoic acid at room temperature would take a very long time. But since the boiling point of water is much higher than that of ethanoic acid, once the water boils, it will produce enough steam to change the state over to gaseous form quickly.

Catalysis

Adding catalysts can also lower the boiling point of a liquid. Catalysts are substances that speed up a chemical reaction but are not consumed in the process. The boiling point of ethanoic acid can be lowered by adding catalysts like powdered zinc or aluminum. This is because the presence of a catalyst lowers the activation energy needed for a reaction to occur so that the reaction will happen quicker.

Molecular Weight

The higher the molecular weight of a molecule, the more energy it takes to break the intermolecular forces between the molecules. This means that the higher the molecular weight, the higher the boiling point. The boiling point is relatively low because its molecular weight is quite low. If the molecular weight was increased, then the boiling point would also increase.

Concentration

The boiling point can also be affected by concentration. The higher the concentration of a compound in a solvent, the higher its boiling point will be. This is because increasing the concentration increases the number of molecules present in a given volume, which means that there are more interactions between molecules (intermolecular forces). So it becomes more difficult for them to break away from one another and vaporize.

Polarity

The boiling point of ethanoic acid is also affected by the polarity of the solvent. In general, the more polar a solvent is, the more easily it can evaporate and the lower its boiling point will be. Ethanoic acid only boils at 118.1 degrees Celsius in non-polar solvents such as CYCLOHEXANE, hexanes, and carbon tetrachloride. In polar solvents like ethanol and acetone, ethanoic acid boils at a much lower temperature, about 90 degrees Celsius. This is because ethanol and acetone are capable of hydrogen bonding with water molecules in the solution. After all, they contain hydroxyl groups.

The ability to hydrogen bond allows water to form a much stronger interaction with other molecules than would otherwise be possible without such interactions (which makes them very polar), which means that when water is present, it becomes more difficult for other molecules to evaporate. So the boiling point of the solution is lowered.

Conclusion

So these are some of the things that can change the boiling point of ethanoic acid. Understanding the different factors that change the boiling point makes it easier to understand why a certain compound has a certain boiling point.