Boiling Point of Salt Water

Explanation to boiling point of salt water:

Substances or liquids in their pure form have a fixed boiling point under specific environmental conditions. However, a mixture of two substances has a boiling point different from that of either substance. I like to share this Density of Salt Water with you all through my article.

Boiling Point of a Mixture:

If another substance like ethyl alcohol or salt is added to water, generally, the boiling point of the mixture (or solution) will be different from that of water in its pure form. For example pure water boils at 100 degrees Celsius (212 Fahrenheit) but a mixture of 95.6% ethanol and 4.4% water (percentage by weight) has a boiling point of 78.2 °C. Moreover, it is an azeotrope, i.e. a solution which retains its constituents in the same proportion through the process of boiling. This prohibits purification of alcohol beyond 95.6% (by weight) purity using the process of distillation.

The case of salt water is other way round, where mixing of salt results in an increase of boiling point of water.

Boiling Point of Salt Water:

For pure water, the boiling point is 100 degrees Celsius (212 Fahrenheit) and addition of alcohol serves to lower the boiling point to 78.2 °C. With common salt (Sodium Chloride or NaCl) the case is different and the boiling point of salt water rises by about half a degree Celsius for every 29 grams of salt dissolved in one liter of water or in other words to raise the boiling point of the solution by 1 °C, one needs to add about 58 grams of salt to one liter of water. Please express your views of this topic Coulomb's Law Formula by commenting on blog.

A Scientific Explanation to Rise in Boiling Point of Salt Water:

When common salt or Sodium Chloride is dissolved in water it gets ionized resulting in Na+ and Cl- ions occupying a few of the spaces between the molecules of water. As a result when this solution is heated water molecules are left with less free space despite their increased kinetic energy with increase in temperature. This results in a lesser number of collisions and hence a there is a lesser release of water-vapor molecules. Thus there is a lower vapor pressure compared to pure water at the same temperature. Hence, a higher temperature is necessary to provide more energy for the vapor pressure of salt water to reach and exceed atmospheric pressure to begin to boil.