Comparison Of Volatility By Rate Of Evaporation
A. Comparison of Volatility by Rate of Evaporation
Volatility describes how easily a substance will vaporize (turn into a gas or vapor). A volatile substance can be defined as (1) a substance that evaporates readily at normal temperatures and/or (2) one that has a measurable vapor pressure. The vapor pressure of a substance is the pressure at which its gaseous (vapor) phase is in equilibrium with its liquid or solid phase. It is a measure of the tendency of molecules and atoms to escape from a liquid or solid. At a given temperature, a substance with a higher vapor pressure will vaporize more readily than a substance with a lower vapor pressure. Intermolecular Forces is one of the factors that affect the volatility of a substance. The stronger the intermolecular forces in a solution, the less volatile the solution is and vice versa. Intermolecular forces are forces of attraction and repulsion between molecules that hold molecules, ions, and atoms together. The intermolecular forces that can be present in a solution are london dispersion forces, dipole-dipole force, hydrogen bonding and ion-dipole forces.
In this experiment the substances that were used were acetone, methanol, water, 1- butanol and ethyl acetate. Acetone is the organic compound with the formula (CH₃)₂CO. It is a colorless, volatile, flammable liquid, and is the simplest ketone. It takes 21 seconds for it to completely disappear. It was the first to evaporate among all tested substances. The reason for this is that this molecule is not attracted to another molecule of Acetone by hydrogen bonding because although there are hydrogen molecules they are not bonded to an Oxygen, Fluorine or Nitrogen. In other words it has no H's that are bonded to F, O, N, or Cl - i.e. there are no slightly positive H atoms. Acetone molecules attract each other since they are both having permanent dipoles. This type of IMF, which is weaker than H bonds, is called dipole-dipole interactions. The weaker the intermolecular
Volatility describes how easily a substance will vaporize (turn into a gas or vapor). A volatile substance can be defined as (1) a substance that evaporates readily at normal temperatures and/or (2) one that has a measurable vapor pressure. The vapor pressure of a substance is the pressure at which its gaseous (vapor) phase is in equilibrium with its liquid or solid phase. It is a measure of the tendency of molecules and atoms to escape from a liquid or solid. At a given temperature, a substance with a higher vapor pressure will vaporize more readily than a substance with a lower vapor pressure. Intermolecular Forces is one of the factors that affect the volatility of a substance. The stronger the intermolecular forces in a solution, the less volatile the solution is and vice versa. Intermolecular forces are forces of attraction and repulsion between molecules that hold molecules, ions, and atoms together. The intermolecular forces that can be present in a solution are london dispersion forces, dipole-dipole force, hydrogen bonding and ion-dipole forces.
In this experiment the substances that were used were acetone, methanol, water, 1- butanol and ethyl acetate. Acetone is the organic compound with the formula (CH₃)₂CO. It is a colorless, volatile, flammable liquid, and is the simplest ketone. It takes 21 seconds for it to completely disappear. It was the first to evaporate among all tested substances. The reason for this is that this molecule is not attracted to another molecule of Acetone by hydrogen bonding because although there are hydrogen molecules they are not bonded to an Oxygen, Fluorine or Nitrogen. In other words it has no H's that are bonded to F, O, N, or Cl - i.e. there are no slightly positive H atoms. Acetone molecules attract each other since they are both having permanent dipoles. This type of IMF, which is weaker than H bonds, is called dipole-dipole interactions. The weaker the intermolecular