What is the effect of the following on the separation of the mixture(hexane and toluene)?
a. A soluble, nonvolatile impurity
b. a decrease in barometric pressure
c. an increase in barometric pressure
d. rapid heating rate
I take we are talking about fractional distillation.
a. In terms of the separation a small amount of a soluble nonvolatile impurity will have no effect. There will be a small increase in each of the boiling points, which are already well separated.
b. A decrease in the barometric pressure will bring the boiling points closer together and thus more theoretical plates are needed to achieve separation. Or, if you like with the same apparatus, a poorer separation.
c. An increase in barometric pressure will increase the separation of the boiling points, so less theoretical plates needed. Or, if you like with the same apparatus, a better separation.
d. Not quite sure what is meant by this. Is the implication that the vapour is not at equilibrium?
a. A soluble, nonvolatile impurity: Well, it looks like someone threw in an unexpected guest at the party. This impurity, being nonvolatile, won't evaporate like our main guests, hexane and toluene. So, it might stick around and tag along with our mixture during separation, making the separation a little bit more challenging. It's like trying to separate salt from sugar when someone added some glitter into the mix. Tricky, but not impossible!
b. A decrease in barometric pressure: Ah, the plot thickens! As the barometric pressure goes down, it means the overall pressure in the system is also reduced. This drop in pressure can influence the boiling points of our hexane and toluene molecules. They might decide to turn into gases at lower temperatures than usual. So, separating them might require a gentler touch, like trying to untangle headphones without pulling them too hard - patience and finesse.
c. An increase in barometric pressure: Hold on to your hats, folks! When the barometric pressure rises, it's like giving our hexane and toluene molecules a little boost. The increased pressure can make them stubborn and turn into gases only at higher temperatures. So, separation becomes a bit of a challenge, like trying to convince a cat to take a bath. It's going to take some extra energy and effort!
d. Rapid heating rate: Oh, you want to crank up the heat? Well, things might get a bit chaotic, just like a cooking show gone wrong. With a rapid heating rate, the molecules of hexane and toluene will be forced to evaporate in a hurry. This might lead to a less efficient separation process since they won't have enough time to leisurely make up their minds. It's like trying to choose the perfect outfit in a 5-second time limit. Good luck with that!
a. A soluble, nonvolatile impurity: The presence of a soluble, nonvolatile impurity will not have a significant effect on the separation of the mixture of hexane and toluene. This is because the impurity does not evaporate during the separation process and does not interfere with the vaporization and condensation of hexane and toluene.
b. A decrease in barometric pressure: Lowering the barometric pressure will decrease the boiling points of both hexane and toluene. This will result in a decrease in the temperature required for the substances to vaporize. As a result, the separation between hexane and toluene will be enhanced as the boiling points between the two substances become more distinct.
c. An increase in barometric pressure: Increasing the barometric pressure will raise the boiling points of both hexane and toluene. This will cause an increase in the temperature required for the substances to vaporize. Consequently, it will be more challenging to separate hexane and toluene as the boiling points come closer together.
d. Rapid heating rate: A rapid heating rate can affect the separation process by creating uneven heating and potentially causing some of the mixture to vaporize more quickly than others. This uneven vaporization may lead to incomplete separation and mixing of the components. Therefore, a slow and controlled heating rate is generally preferred for achieving better separation.
To determine the effect of each factor on the separation of the mixture of hexane and toluene, we need to consider the principles and properties of the components involved.
a. A soluble, nonvolatile impurity:
A soluble, nonvolatile impurity means that a substance is present in the mixture that dissolves in the hexane and toluene, but does not easily evaporate. This impurity would not significantly affect the separation of the mixture because it will remain dissolved in the solvent, and it will not affect the volatility or the boiling points of hexane and toluene.
b. A decrease in barometric pressure:
A decrease in barometric pressure lowers the atmospheric pressure, which in turn affects the boiling points of the components in the mixture. Both hexane and toluene have lower boiling points relative to most impurities. As the pressure decreases, the boiling points of hexane and toluene will decrease as well. This can promote the separation of the mixture, as the lower boiling point component (hexane) may vaporize more readily, allowing it to be separated from the higher boiling point component (toluene).
c. An increase in barometric pressure:
An increase in barometric pressure raises the atmospheric pressure. This will have the opposite effect and increase the boiling points of both hexane and toluene. As a result, the separation of the mixture will be more difficult because both components will have higher boiling points, resulting in a smaller temperature difference required to separate them.
d. Rapid heating rate:
Rapid heating rate refers to quickly increasing the temperature in the system. This rate of heating does not directly impact the separation of the mixture. However, it may have an indirect effect on the separation if the heating is too fast. If the temperature increases too quickly, there may not be enough time for the components to separate before the mixture reaches its boiling point, reducing the efficiency of separation.
In summary:
a. A soluble, nonvolatile impurity has little to no effect on the separation of the mixture.
b. A decrease in barometric pressure promotes separation by reducing the boiling points of the components.
c. An increase in barometric pressure hinders separation as it increases the boiling points of the components.
d. Rapid heating rate does not directly affect the separation, but if too fast, it may hinder the efficiency of separation.