Discussion
At a constant temperature, a pure liquid has a vapor pressure that describes the pressure of escaped gaseous molecules that exist in equilibrium at the liquid’s surface. Adding energy to a pure liquid gives more molecules the kinetic energy to break the intermolecular forces maintaining the liquid and raises the overall temperature of the liquid. Eventually, adding energy boosts the liquid’s vapor pressure until it equals the surrounding atmospheric pressure. When this occurs, the pure liquid boils at a temperature called the boiling point.
Distillation uses the characteristic boiling points of pure liquids to separate these substances from a mixture. Once a pure liquid reaches its boiling point, it maintains this temperature as
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However, the measured densities lied below the accepted densities of 0.933 g/mL, 0.900 g/mL, and 0.888 g/mL for methyl acetate, ethyl acetate, and propyl acetate respectively. Refractive indices increased across all groups, including Group 6, from the methyl acetate sample to the propyl acetate sample just as expected from the theoretical refractive index values of the pure liquids. In addition, the refractive index % error calculations of Group 6 indicate that samples 1,3, and 5 produced refractive index values relatively close to the theoretical refractive indices of methyl acetate, ethyl acetate, and propyl acetate respectively. Although no distillation produces a perfectly pure liquid, the lack of relatively constant temperatures seen in the data and plots makes it unlikely that the samples collected by the class distillations had a high level of purity. Evaporation from the samples due to a lack of properly fitting test tube caps also reduced the usefulness of the density and refractive index calculations for determining the closeness of the obtained samples to the pure
Thermodynamics is essentially how heat energy transfers from one substance to another. In “Joe Science vs. the Water Heater,” the temperature of water in a water heater must be found without measuring the water directly from the water heater. This problem was translated to the lab by providing heated water, fish bowl thermometers, styrofoam cups, and all other instruments found in the lab. The thermometer only reaches 45 degrees celsius; therefore, thermodynamic equations need to be applied in order to find the original temperature of the hot water. We also had access to deionized water that was approximately room temperature.
It was learned that changing the volume of the same substance will never change the boiling point of the substance. However having two different substances with the same volume will result in two different boiling points. The purpose of this lab was to determine if changing the volume of a substance will change the boiling point. This is useful to know in real life because if someone wanted to boil water to make pasta and did not know how much water to
The C-H (sp3) hydrogens from our product displayed at wavelength 2959 cm-1 correlates to the methyl groups located on the ends of isopentyl acetate4. A really prominent, strong peak located at 1742 cm-1 shows that a C=O ester stretch is located in the product, along with at 1244 cm-1 the spectrum shows a strong peak representing the C(=O)-O stretch that is crucial to the structure of isopentyl acetate. Shown in my IR spectrum is a weak O-H (H-bonded) peak at 3464 cm-1 which shows that I have an impurity of isopentyl alcohol in my product. Isopentyl alcohol has similar boiling points and density as my product so the impurity could have easily boiled out with the isopentyl acetate during distillation. The isopentyl alcohol was also present in my 1H-NMR spectrum backing up the impurity peak at 3464
...lt in water. Although water is generally considered to boil at 100°C (212°F), water actually boils when the vapor pressure is the same as the air pressure around the water (Physics, 2006). Because of this the boiling point of water is lower in lower pressure and higher at higher pressure. Did you know that baking cookies above 3500 feet above sea level require special cooking directons (Burt, 2004).
Every time the container the substance is in is opened some of it will evaporate, causing the temperature of the liquid to change. As it evaporates, the temperature decreases.
Another way to control the heat is to decrease the distance between the boiling tube. and the container of the. The amount of energy released increases with the number of bonds. present in the chemical substance or fuel. That is because each bond has a certain amount of energy stored in it therefore the more bonds the more energy is stored and more energy is released if these bonds break through the combustion process.
This experiment attempts to produce isopentyl acetate by heating under reflux, which involves heating the mixture in a flask with a condenser placed vertically in the neck since any escaping vapours condense and run back into the flask, by combining isopentyl alcohol with acetic acid and an acid catalyst. The product was isolated using a combination of techniques -- acid-base extraction, drying, and distillation -- and was characterized by its boiling temperature and its refractive index.
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).
The primary goal of this experiment was to determine which types of glassware are the most accurate and precise in measuring substances. Another goal of this experiment was to help familiarize ourselves with the different types of glassware, and how we should handle the laboratory equipment. The accuracy and precision of a particular type of glassware is important because it allows for accurate measurements when performing different experiments. It also allows us to differentiate between glassware that is better for containing substances versus glassware that can deliver substances more accurately. In order to measure the accuracy and precision of the different types of glassware, we first chose seven different types of glassware. The general
There would be a change in the amount of energy given off that is getting greater, the more carbon atoms in the fuel, the more there are more bonds to be broken and formed, thus producing more energy. In a chemical reaction, bonds in the reactant molecule are broken and new ones are formed. Atoms are rearranged and rearranged. Energy has to be put in to break bonds, and energy is given out when bonds are formed.’ When the total energy put in is greater than the energy put out, the substance cools down (it is endothermic).
For water at 1 atm, the melting point and boiling point is 0 °C and 100°C respectively. Water reaches the maximum density at 4°C. The density of ice is lower than that of water. The molecules are in constant motion and the strong hydrogen bonding leads to the closed packing of water molecules.
Methanol and Ethanol have differences as Methanol melts at a higher temperature and boils at a lower temperature than Ethanol. Higher alcohols, which include Butanol and Propanol, have a higher molecular weight and this is why Butanol is used in perfumes. Ethanol, which is sugar based, with its low freezing point, has a specific use as an antifreeze for cars and other vehicles. GRAPH Tripod Matches Goggles Method: To begin with, I choose one of the four different alcohols. I weigh beforehand in the spirit burner.
It is based on physics, and the 2nd law of thermodynamics. A liquid is vaporized through compression, which requires kinetic energy. This draws the energy needed from the direct area; causing a loss in energy and then it
its state (Solid, liquid, gas); thus water has a higher melting point and a higher boiling
The process of distillation has been used by humans for years to create alcoholic beverages. Distillation is the process of boiling a pair of liquids with different boiling points and then condensing the vapors above the boiling liquid in an attempt to separate them. One might suspect that the mixed two liquids of different boiling points could be separated simply by raising the temperature to the lower boiling point of the two liquids. However, this is not the case. The two liquids “boil” together at some temperature between their two boiling points.