There are many concepts explored throughout “Enthalpy Vaporization of Water”.
First of all, the purpose of this lab was to determine the water’s vapor pressure at different temperatures as well as to measure the molar heat of vaporization of water using the Clausias Clapeyron equation. The first concept out of many represented in this lab is the ideal gas law. The ideal gas law is used to get the number of moles of air trapped in the 10 mL graduated cylinder. Once we cooled the system so that water vapor is extremely minute, and then we determined the number of moles of air using the ideal gas law. The number of moles of air equals to the pressure (in atm) times volume divided by constant times temperature. One would assume that when the water is heated to 80 degrees, the number of air molecules in the air bubble would decrease, but it actually stays constant. This is due to the fact that there is no air coming in or out of the cylinder. As the temperature gets closer to 80 degrees, the number of air molecules stays the same but the water vapor increases. And the bubble expands to keep the pressure at the same level. The ideal gas law was also used when the partial pressure of air in the gas mixture is calculated. This is gotten from number of moles multiplied by the constant and the constant and the whole thing divided by the volume.
Next Dalton’s law of partial pressure is used. The mixture of gas in the graduated cylinder was filled with two things: water vapor and air. Using the Dalton’s law, it can be concluded that the total pressure is equal to the pressure of air and the pressure of water vapor added together. This is an endothermic reaction which means that it absorbs heat, and when a reaction gains heat, it is repres...
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...inty between 1.0% (0.1/10.00*100) and 2.13% in the measured volume and 0.1/4.70*100). We also used a digital thermometer that allowed us to read the temperature readings from five degrees celcius to eighty degrees celcius. Since the digital thermometer have an absolute accuracy of plus or minus one degree celcius, it gives a percent uncertainty between 0.125 % (0.1 / 5.00 * 100) and 0.2 % (0.1/ 80.0 * 100). One of the difficulties we faced during the lab is reading the inverted graduated cylinder. To account for the inverse meniscus, we subtracted 0.2 mL from all the volumetric measurements to account for that. Volumetric uncertainty is the most important in determining the accuracy of this experiment since we are constantly checking for the volume throughout the lab. It also is the factor that gives the highest percent uncertainty out of all the instruments used.
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.
Furthermore, using a graduated cylinder with markings below the 100 mL line would have allowed for more accurate measurements of the initial volume of air in the graduated cylinder.
When the liquid level is above the calibration line on the pipette, remove the bulb quickly and put your thumb or index finger over the pipette. Carefully “roll” finger to the side and allow the liquid to drop until the meniscus is level with the mark. Then hold the pipette over the flask to receive the liquid and remove the finger. Allow the liquid to drain out.
The purpose of this lab was to calculate the specific heat of a metal cylinder
The boiling point of a substance is “the temperature at which the total vapor pressure of the liquid is equal to the external pressure” (Gilbert & Martin 2011). Boiling point is the point at which the evaporation rate of a given liquid increases as bubbles are formed. The boiling point is usually determined by “reading the thermometer during a simple distillation” (Gilbert & Martin 2011). However for the purposes of this lab, a miniscale method was used to determine the boiling point. This method requires for a liquid to be heated using the apparatus seen in Figure 1. A thermometer is placed just above the liquid at a height where the thermometer is able to measure the vapor temperature of the liquid, not the liquid itself. As the liquid heats, the temperature rises until it reaches an equilibrium where it cannot increase any
Discussion: The percent of errors is 59.62%. Several errors could have happened during the experiment. Weak techniques may occur.
In this experiment, there were several objectives. First, this lab was designed to determine the difference, if any, between the densities of Coke and Diet Coke. It was designed to evaluate the accuracy and precision of several lab equipment measurements. This lab was also designed to be an introduction to the LabQuest Data and the Logger Pro data analysis database. Random, systematic, and gross errors are errors made during experiments that can have significant effects to the results. Random errors do not really have a specific cause, but still causes a few of the measurements to either be a little high or a little low. Systematic errors occur when there are limitations or mistakes on lab equipment or lab procedures. These kinds of errors cause measurements to be either be always high or always low. The last kind of error is gross errors. Gross errors occur when machines or equipment fail completely. However, gross errors usually occur due to a personal mistake. For this experiment, the number of significant figures is very important and depends on the equipment being used. When using the volumetric pipette and burette, the measurements are rounded to the hundredth place while in a graduated cylinder, it is rounded to the tenth place.
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.
Start with the hot water and first measure the temperature. Record it. 8. Then pour 40 ml into the beaker. You can measure how much water was used by looking at the meniscus.
One possible source of experimental error could be not having a solid measurement of magnesium hydroxide nor citric acid. This is because we were told to measure out between 5.6g-5.8g for magnesium hydroxide and 14g-21g for citric acid. If accuracy measures how closely a measured value is to the accepted value and or true value, then accuracy may not have been an aspect that was achieved in this lab. Therefore, not having a solid precise measurement and accurate measurement was another source of experimental error.
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.
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
There is also the potential of human error within this experiment for example finding the meniscus is important to get an accurate amount using the graduated pipettes and burettes. There is a possibility that at one point in the experiment a chemical was measured inaccurately affecting the results. To resolve this, the experiment should have been repeated three times.
We found the value of heat taken from the brass weight also, using the same equation.
The liquid-vapour mixture of the refrigerant at pressure and temperature is evaporated and changed into vapour refrigerant at constant pressure and temperature.