Free Determination of Boiling Point Essay Sample
In the distillation of a pure substance (e.g., water) why does all of the water not vaporize at once when the boiling point is reached?
This can be explained for the perspective that, boiling point is the point at which the substance reaches certain temperature and begins to vaporize. For vaporization to take place, water molecules need to have accumulated energy. This energy in the water molecules can only be achieved during boiling point. It is during boiling point that these molecules will have the energy to boil away. When boiling, these molecules carry away with them the energy supplied during heating. Therefore, for the whole sample to vaporize completely there has to be constant supply of heat so as to enable boiling. It is due to this reason that the whole sample cannot evaporate at once. This is because the molecules break at different levels depending on the accumulated amount of energy to enable them to vaporize.
Explain the three types (ignore ion-ion) of intermolecular attractive forces and how they affect a boiling point?
Intermolecular forces can be defined as the attraction between forces. This is also known as van der waals forces. The three types of intermolecular attractive forces are:
It states that, unsymmetrical distribution of electronic charges leads to positive and negative charges in the molecules. These molecules are referred to as dipoles. In relation to boiling, the positive molecules lines up to attract the negative ones, hence they entice boiling. These attractive forces are less than the full charges carried by ions in ionic crystals.
This one is found in both polar and nonpolar molecules. It operates in the sense that, due to uneven distribution of charge, an atom which might be nonpolar becomes unstable and liable to movement of its electrons, hence becoming a polar. This motion can be related and attributed to the same motion in molecules during boiling.
The third and last force is Hydrogen bonds. This is where a hydrogen nucleus has a high concentration of positive charge. It operates in a more or less manner just like the other two forces. What happens is that, a hydrogen atom is bonded to a highly electronegative atom, and then its positive charges attracts the surrounding electrons, hence pairing. The molecules build into a big unit. In relation to boiling, the molecules are charged.
In each pair which would be expected to have the higher boiling point? Briefly explain your choices.
t-butyl alcohol (2-methyl-2-propanol) or n-butyl alcohol (1-butanol) [branched verses single chain]
1-butanol (CH3CH2CH2CH2OH) or diethyl ether (CH3CH2OCH2CH3) [alcohol verses an ether]
To my opinion, alcohol verses an ether, would have a higher boiling point. The reason for this is because it has a lower boiling point due to its loose molecules, which acquire energy easily, hence boiling faster than branched verses single chain which has more attached molecules which takes time to acquire energy.
In fractional distillation, liquid can be seen running from the bottom of the distillation column back into the
Distilling flask what effect does this returning condensate have on the fractional distillation?
The effect fractional distillation is that, there is separation of a mixture of volatile liquids by means of fractional distillation, and as a result there is composition of vapor coming from the liquid mixture, which is different from the one which was in the flask.