Analysis:
2. Of the alcohols tested 1-Butanol was found to contain the strongest intermolecular forces (IMF) of attraction, with Methanol containing the weakest. It was discovered through experimentation that Methanol induced the highest ?T of all alcohols tested, and that conversely 1-Butanol induced the lowest ?T. The atomic structure of all four alcohols is very similar, as starting with 1-Butanol a CH2 group is lost as you move from 1-Butanol to 1-Propanol to Ethanol and then again to Methanol. Each structure is fairly linear and contains an H-bond with Oxygen, so the real change is found in the loss of the CH2 group, this lowers the liquid’s Molecular Mass, thus lowering the London forces as you move from 1-Butanol through 1-Propanol and Ethanol, to Methanol. Since the IMF within 1-Butanol are stronger than the other three alcohols, it has a higher ?Hvap. During the experiment, all 4 alcohols tested (indeed all 7 liquids tested) were exposed to the room temperature air of the laboratory. Thus the free-floating gas particles in the lab air were able to impart Kinetic Energy to the liquids being sampled, at a constant rate under fairly controlled and consistent conditions. This resulted in the kinetic energy being absorbed into the liquid from the air surrounding the temperature probe, causing said air to drop in temperature, which was duly reported by the probe, and used to calculate the ?T of the liquid. In the case of 1-Butanol the ?T was very small, indeed smaller than any other liquid tested. It also took a very long time comparatively to reach its minimum, as opposed to a liquid with a high ?T like Methanol which was quite fast. An inverse relationship is found then between the ?T and the strength of the IMF ...
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... each liquid. With molecular weight, as the weight increased the strength of the IMF, namely London forces increased as well. Then as the IMF increased the propensity of the liquid to evaporate was lessened, leading both to a lower ?T and a slower time to reach the ?T in general.
Conclusion:
In conclusion it was found that there is an inverse relationship between the strength of the intermolecular forces holding molecules together and the rate at which those molecules evaporate. As the bonds get stronger it takes more energy to separate them and allow the molecules to escape into the vapor phase. This was the goal of the lab and it was met. Significant improvements could only be made at a considerable investment in time and expense and are unnecessary as the lab procedure as outlined was more than enough to derive the relationship needed through comparison.
3. When the volume changes were made and the reaction restarted, the reaction rates were affected. This is because in a low pressure system, the rate of the reaction would be slower because of the space between the particles being bigger and as a result of this, time between collisions (necessary for reactions) also increases.
The heat makes the molecules in the mixture expand and move slower than when they are in colder temperatures (source 1). The molecules are like people when it comes to how they react to heat and coldness. When the molecules are cold, they like to be very close to one another and the molecules move fast because they are “shivering” (source 2).This is just a one of many examples and comparisons that I am going make throughout this paper. Some of the examples will be very cheesy. I am going to give a warning. When the molecules are hot, they like to be far apart from one another (source 1). They even might start to sweat like humans, too. The molecules have some energy too, but the molecules just do not have as much energy when they are hot. They like to be lazy like many humans do in hot weather (source 1).
and Karttunen, M. (2006) “Under the Influence of Alcohol: The Effect of Ethanol and Methanol on Lipid Bilayers”, Biophysical Journal, 90(4), 1121-1135
...ns. This is related to Gay –Lussac’s Law. This is because temperature is the same thing as kinetic energy, and as the energy rises, the particles within the substance start to rapidly collide with one another, and they exert increased pressure. This law is written out as: .
On earth, substances tend to exist in one of three phases; either a solid, liquid, or gas. While solids and liquids have defining factors such as volume, and for solids only, a shape, gases exhibit neither of these. Gases naturally take the shape of and expand into the volume of the container, and change when placed in different surroundings. As gases are constantly moving around and colliding with the walls, they exert a force, or pressure, on the walls of its container. Pressure is one of the characteristic behaviors that gases exhibit, but due to their nature, various factor effect the pressures that a gas can exert. Towards the end of the eighteenth century, scientist began to stumble upon these various factors that affect gases, especially
The temperature dependence of viscosity can be very strong; for example, in motor oil, η can diminish ten-fold with only a 10% increase in the absolute temperature. Therefore, if temperature is not uniform but varies with position in a flow, one cannot obtain a single value for its viscosity. The other dependence of viscosity, on shear rate, is a non-Newtonian property of some fluids; this effect is called “shear thinning” if η diminishes with increasing γ.31 Shear thinning can be avoided in an experiment by applying a small shear stress, so that conditions are relatively close to
This is a result of a more favorable entropy contribution, due to the reduction of apolar molecular surface area during the activation process4. The substituent of the reaction does affect the rate enhance but depended on the compounds being used. The Gibbs energy transfer plot of the reaction of compounds 1.1 and 1.5 from figure 1, reveals that the rate acceleration in water relative to the alcohol was due to the destabilization of the initial state. The stabilization of the transition state relative to the initial step was proposed to be a consequence of the reduction of hydrophobic surface
Alcohol is an ethanol containing substance that is a common beverage in many social and private settings. Alcohol is also a teratogen, therefore alcohol co...
Methanol was the most polar among 3 alcohols used in this part, hence was soluble in water as both water and methanol were polar. However, methanol was partially soluble in hexane because the Van der Waals interaction between methanol
2. What observation leads you to believe there is a force of attraction between water
The overall basis of this experiment is to take two compounds, in this case toluene and hexane, distill both and observe a constant boiling point in order to later distill a more complex two component mixture which will provide the pure compound. The distillation process begins with heating a liquid to a boiling point, in this experiment that being hexane and toluene separately to start off, the liquid evaporates forming a vapor. A stir bar was provided in order to ensure that an even boiling of the liquid could happen and therefore produce a place where bubbles of vapor can form. We then recorded the temperatures after collecting different amount of Ml hexane distillate, the same steps repeated for toluene as well. The distillate is a purified
Investigation to Find the Relative Energy Release of Five Alcohols: Ethanol, Methanol, Propanol, Butanol and Propanol
Therefore, the relationship between pressure drop and boil-up rate means that more volume of vapour educed per unit time results in more restriction of the holes in the sieve tray and that caused by passing of vapour through the liquid on top of the tray. Hence, the higher the velocity, the higher the boil-up rate and so does the overall pressure drop.
· A. How the volume of water affects the time that it takes to boil.
Alcohol is a class of organic compounds that is characterized by the presence of one or more hydroxyl groups (-OH) attached to a carbon atom. Alcohol was unknowingly produced centuries ago when fermentation occurred to crushed grapes (Pines, 1931). In today’s society alcohol is produced for the use of household products such as varnishes, cleaning products, but is more commercially important in the liquor business. A chemical process called fermentation accomplishes the production of ethanol, the alcohol or liquor. From there, the ethanol goes through distinct processes to become the dark and clear liquors on the store shelves.