Refrigeration, the production of cold, is an essential practice for present-day living. It is used in a many place like the processing and preservation of food, conditioning of air for comfort, manufacture of chemicals and other materials, cooling of concrete, medical applications etc. Refrigeration is defined as the science of maintaining the temperature of a particular space lower than its surrounding space. Refrigeration and air conditioning involves various processes such as compression, expansion, cooling, heating, humidification, de-humidification, air purification, air distribution etc. In all these processes, there is an exchange of mass, momentum and energy. All these exchanges are subject to certain fundamental laws. Hence to understand and analyses the refrigeration and air conditioning systems, a basic knowledge of the laws of thermodynamics, fluid mechanics and heat transfer is essential.
Then, we multiply the result by 100 to get a percentage number. An example calculation from the 5.00mL pipet is: ((5.00mL - 4.9178mL)/5.00mL)*100 = 1.6438%. The percent error allows us to see which type of glassware is the most accurate at measuring substances. From our results, we concluded that the variable auto pipettor was the most accurate, since it had the lowest percent error, at 0.0500%. The volumetric pipet, volumetric flask, and burette, all had similar percent errors at 1.0430%, 0.6394%, and 0.6619%, respectively. These results indicate that these glassware types are still very accurate. Next, the graduated cylinder had a percent error of 1.6400%, which is still relatively low, indicating that the graduated cylinder is also very accurate. The beaker and erlenmeyer flask both had higher percent errors, at 7.5218%, and 9.4146%, respectively. The beaker and the erlenmeyer flask were not accurate at measuring substances. This is perhaps because they are larger, and are meant to hold larger volumes of water, or they are meant to contain and pour substances. After finding out
The purpose of this experiment is to try to find the original temperature of the hot water in the heater using the 60 degrees C thermometer. Use your 60°C thermometer, and any materials available in your laboratory, to determine the temperature of the water in the coffee pot. During this experiment we calculated the original temperature of a heater after it had been cooled down, and we did this by measuring hot, cold, and warm water, with a thermometer that had tape covering 60 degrees and up. When preformed each of these experiments with each temperature of water, plugging them into the equation (Delta)(Ti – hot – Tf) T Hot x Cp x Mass(Cold) = (Delta)(Tf – Ti – Cold) T Cold x Cp x Mass(Hot)(d
...particles could have been blown away while being transferred into the beaker. Also, reading the thermometer incorrectly could have resulted in experimental error. Recording the data collected at specific temperatures was a major part of the experiment to perform calculations to determine the enthalpy and entropy.
Introduction: The purpose of this experiment was to isolate eugenol or clove oil from cloves using steam distillation and determine whether it is an efficient way to carry out this experiment. Also, TLC and 1H NMR were preformed to analyze the purity of the isolated eugenol.
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.
Next law important to divers is Charles’ law also referred to as Gay-Lussac’s Law. It states that given a constant pressure, the volume of a gas varies directly as the absolute temperature. When metals get hot, it expands. Same thing happens to gases. What Charles’ Law says is that if you take a volume of air in a SCUBA tank, and keep it at a constant pressure, you can increase your volume simply by heating it. When a SCUBA cylinder is filled, the friction of the air entering the cylinder heats things up from the inside out. This makes the surface of the cylinder warm to the touch. Many dive shops will overfill cylinders by about 10% of the maximum allowed. The reason is diving shops will compensate and put more air in the cylinder than would be necessary for a typical dive because the cylinder will eventually cool down and get to the allotted maximum. If the maximum is 3000 psi (206 bar), the dive shop will fill a cylinder to 3300 psi (227 bar). Once it cools, it will go down to 3000 psi again.
9. Repeat step #8. Using a pipet, add small amounts of boiling water from the hot plate to the water bath and collect pressure and temperature data. For each new temperature, record the air pressure and vapor pressure. Continue until you have gathered 6 measurements that range from room temperature to 40 °C.
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.
Background: The purpose of this lab was to use parts of the combined gas law formula to understand the relationship between unknown variables. We were able to obtain two unknown variables by holding two different variables constant. For this experiment the variables we measured were pressure (P), volume (V), temperature (T), and amount of substance (n). To achieve our answers we used the combined gas law which is derived from Boyle’s, Charles, and Gay-Lussac’s gas laws. In this experiment we also relied heavily on rigid and non-riged containers and well as an open and closed system. All our points were also graphed to help identify whether the relationships were inversely or directly related.
The purpose of Lab 4: Gas Wars was to recognize the gas law relationship among pressure, volume, temperature, and as well as mole; to articulate gas laws; and to employ data by using a spreadsheet. The gas laws that are going to be focused on are Boyle’s Law, Charles’s Law, Avogadro’s Law, and the Universal Gas Laws. In Boyle’s Law pressure and volume are inversely proportional; when one increases the other decreases. Charles’s law states that volume and temperature are directly proportional; when one increases the other increases. While in Avogadro’s Law claims that volume and the number of moles are proportional while at standard temperature and pressure (STP). The Universal or Ideal Gas Law equation can be deprived from the other laws;
It was then placed in the ice bath, in which immediately the can slightly collapse on itself. In part two of the experiment, the prepared ice bath temperature measured at 1°C (T2). While the heated bath temperature stabilized around 85°C (T1) after 5 minutes, where it also began to simmer. The test tube with the rubber stop in the heated bath had no water for the entire 5 minutes. When the test tube was placed inside the ice bath for 5 minutes water appeared to flow inside the test tube. The amount of water that flowed into the test tube measured at 5 mL (Vw). When determining the volume of the test tube in the 100 mL graduated cylinder with 30 mL of water, it displaced the water up to 74 mL. Thus determining the volume of the test tube as 34 mL
As the pressure drop increases in the column, it is observed that the degree of foaming becomes more violent and more spread out. When the pressure drop is relatively high, it means that the pressure exerted by the vapour is insufficient to hold up the liquid in the tray, causing the gas bubbles to appear on top of the sieve trays. To add on, the higher the pressure drop, the higher the velocity of the vapour passing up the column. As a result, more vapour will penetrate the liquid and more bubbles formation is observed. Due to more bubbles formation, the degree of foaming are more agitated, rapid and spread out.
In a 100ml beaker 30mls of water was placed the temperature of the water was recorded. 1 teaspoon of Ammonium Nitrate was added to the water and stirred until dissolved. The temperature was then recorded again. This was to see the difference between the initial temperature and the final temperature.
The last part of experiment 5, was learning about specific gravity and temperature. Specific gravity does not have any units, it is unitless. When measuring for the temperature, we used a thermometer to calculate the Celsius of the water, 10% sodium chloride, and isopropyl alcohol. The specific gravity uses a hydrometer to measure the gravity of the liquids. Using the hydrometer, to figure out the measurements we have to look at it from top to bottom. The water for specific gravity was .998 while the temperature of it was 24