The dsc technique is especially advantageous for expensive chemicals. Regiospecific analysis has shown that in coconut oil, lauric and linoleic acids are esterified mainly in the sn2 position and oleic acid and saturated acids in the sn positions table 2. Edible oils as practical phase change materials for thermal. Save the data file and email it to everyone in your group andor save it on usb drives. What happens to the molecules in a substance during the plateau reigons of the curves and the nonplateau reigons of the curves. A closer examination of the plateau region of the heating curve would reveal tiny zigzags in the temperature, like the teeth of a hacksaw blade. To determine the freezingmelting point of lauric acid from the cooling heating curves. Remove the test tube of lauric acid from the hot water bath. The lauric acid can be saved and reused from year to year. Melting and freezing stearic acid resource rsc education. Add energy, and the rigid solid structure breaks down to the liquid state, water. As soon as it is melted enough to stir the lauric acid with a thermometer, carefully do so.
Stay on the safe side and stick with food amounts if you are. Continue this procedure until the temperature of the sample reaches 25 c if lauric acid or 40 c if using paradichlorobenzene. This practical takes quite a long time to carry out. Heating curves and cooling curves show the temperature changes of the heating cooling of a certain substance. Heating and cooling curve of lauric acid objectives.
I drew lauric acid heating and cooling curves for a lab. Prepare stearic acid and lauric acid mixtures of varying composition. Phase change materials, thermal energy storage, latent heat, fatty acid, dsc. If the lauric acid is not above 50c, obtain another lauric acid sample and begin again. Measure the thermal characteristics heat capacity, latent heat of fusion, and melting temperature of stearic lauric acid mixtures using differential scanning calorimetry. Vapor pressure data for fatty acids obtained using an. It is the main acid in coconut oil and in palm kernel oil, and is believed to have antimicrobial properties. Properties of lauric acid and their significance in.
Lauric acid or systematically, dodecanoic acid, is a saturated fatty acid with a 12carbon atom chain, thus having many properties of mediumchain fatty acids, is a bright white, powdery solid with a faint odor of bay oil or soap. Latent heat thermal energy storage lhtes is a promising technique. The thermal and heat transfer characteristics of lauric acid during the melting and solidification processes were determined experimentally in a vertical double pipe energy storage system. If i had increased the lauric acid, how would that affect the various segments of the cooling. Lauric acid is safe for pregnant and breastfeeding women in food amounts. The binary eutectic mixture consisting of lauric acid 40% and myristyl alco hol 60% is. Discover lauric acid, a fatty acid found in coconut oil. The freezing point of my graph is about 42 degrees celsius. As the acid starts to melt carefully put a thermometer in the test tube. Computer 4 using freezingpoint depression to find molecular. A slight alternative to this experiment is to plot only the cooling curve. Lauric acid, although slightly irritating to mucous membranes, has a very low. You are likely to have used salol or stearic acid in a school practical lesson to make your own cooling curve.
Fatty acids as phase change materials pcms for thermal energy. Lower your sample into the water when you reach a temperature of about 40oc. Heating and cooling curves the heating and cooling curves of lauric acid dodecanoic acid, c 12 h 22 o 2 introduction lauric acid, as a component of triglycerides, comprises about half of the fatty acid content in coconut oil and in palm kernel oil not to be confused with palm oil, otherwise it is relatively uncommon. The cooling curve of stearic acid introduction matter around us exists in three common statessolid, liquid, and gas. The other partner will read off the temperature of the sample at each. The active substance of the biocidal product is lauric acid.
When you are completely done collecting data for the day, the freezing temperature of. Learn what studies have to say about its ability to combat conditions from acne to alzheimers disease. A similar trend is in the distribution of lauric and oleic acids in palm kernel oil. Health benefits of lauric acid from coconut oil healthyoil. Lauric acid, or dodecanoic acid is the main fatty acid in coconut oil and in palm kernel oil, and is believed to have antimicrobial properties. Cooling curves stearic acid cooling from a liquid to a solid changes in state cause bonds to be broken or made. Given the graph below that represents the uniform cooling of a sample of lauric acid starting as a liquid above freezing point. Heating and cooling curves the heating and cooling curves of lauric acid dodecanoic acid, c 12 h 22 o 2 introduction lauric acid, as a component of triglycerides, comprises about half of the fatty acid content in coconut oil and in palm kernel oil. Cooling curve fill a 400ml beaker threequarters full with cold tap water. The tgadtg curves of pure lauric acid, figure 4, exhibited a region of significant mass loss. Heating and cooling curves of stearic acid using thermometer lab purpose. This lab has students melt and freeze lauric acid dodecanoic acid and then develop their own heating and cooling curve.
Pdf in order to obtain the suitable phase change material pcm with low phase. In any pure substance, changes of physical state occur at constant, discrete. Lauric acid or systematically, dodecanoic acid, is a saturated fatty acid with a 12carbon atom chain, thus falling into the medium chain fatty acids, is a white, powdery solid with a faint odor of bay oil or soap. A study tested regular consumption of lauric acid leads to fewer calorie intake and better metabolism in its subjects. Lauric acid is a powdery white solid at room temperature. Stearic acid binary eutectic mixture in latent heat. Sep 30, 2008 what is the effect of increasing amount of substance on coolingheating curves. The salts and esters of lauric acid are known as laurates. It is a nontoxic acid commonly found in the milk of some mammals.
Examine the effects of the heating and cooling of a pure substance through phase change. Heating and cooling curves of the latent heat storage unit undergoing. Salol has a melting point of about 45c and stearic acid has a melting point of about 69c. Lauric acid, although slightly irritating to mucous membranes, has a very low toxicity and so is used in many soaps and shampoos. Continue heating the water to a temperature of 50c 55c. Heat the lauric acid in the 60 oc water until it is at about 55 oc or the stearic acid to 75 oc. With a very slight up and down motion of the temperature probe. We also determined coconut oils heat capacity and thermal conductivity as. Nov 10, 2012 highlights vapor pressure data of fatty acids were measured by differential scanning calorimetry. Fortunately, there are other food sources where you can get higher amounts of lauric acid. The water temperature should rise as the stearic acid cools and it should continue to rise even as it changes state.
The metabolic and physiological properties of lauric acid account for many of the properties of coconut oil. Experimental investigation on melting heat transfer characteristics of. Thermal characterization of lauric acid and stearic acid binary. Energy enters the thermal account raising the temperature and then is immediately transferred to the phase account lowering the temperature as the particles break free from their mutual attractions. Lauric acid is the most potent fatty acid in raising plasma total cholesterol, but dairy content is only 3. Heating and cooling curves the heating and cooling curves of lauric acid dodecanoic acid, c12h22o2 introduction lauric acid, as a component of triglycerides, comprises about half of the fatty acid content in coconut oil and in palm kernel oil not to be confused with palm oi. Cooling curve of lauric acid the purpose of this lab is to observe the heating curve of water, learn skills to analyze heating curve, and use graph to predict the melting point of lauric acid. To practice techniques of heating materials using the bunsen burner. Lauric acid producttype 19 attractants and repellents.
During this heating process, what physical change is happening to the lauric acid. We are trying to find out if water takes longer time to cool down if the starting temperatures are different. What is the effect of increasing amount of substance on. Lauric acid and coconut have been linked with weight loss for some time. They can observe the melting and freezing points of the acid and can plot a graph. Thermal and catalytic pyrolysis of dodecanoic acid on. Heating curves and cooling curves show the temperature changes of the heatingcooling of a certain substance. The study is focused on the melting of lauric acid in a rectangular thermal storage unit. Thermal and heat transfer characteristics in a latent heat. Time 50 minutes for data collection 30 minutes for graphing objectives 1. Quickly remove the thermometer from the lauric acid and thoroughly wipe the lauric acid off with a tissue kimwipe. Using a test tube holder, transfer the liquid lauric acid tube to the 30oc water bath and record the temperature at 30second intervals until the temperature reaches at least 40oc.
Just like heating curves, cooling curves have horizontal flat parts where the state changes from gas to liquid, or from liquid to solid. There is some concern about using lauric acid during breastfeeding because lauric acid passes into breast milk. Reading heating and cooling curves lauric acid cooling curve heating and cooling curve of an unknown substance lab a virtual lab that will plot the heating and cooling. However, look at where the heating curve intersects the cooling curve. Health benefits of lauric acid from coconut oil healthy.
Return the lauric acid in the test tube to dispensing area. Heat the test tube of lauric acid gently until it reaches at least 55. Highlights vapor pressure data of fatty acids were measured by differential scanning calorimetry. In this class practical students take the temperature of stearic acid at regular intervals as they heat and cool it. Properties of lauric acid and their significance in coconut oil bibliographic information language. It is not known how lauric acid might work as a medicine. Synonyms of this fatty acid are dodecanoic acid, laurostearic acid and dodecoic acid.
Antoine constants were obtained for the selected fatty acids. If i had increased the lauric acid, how would that affect the various segments of the coolingheating curves. Sample data for the heating and cooling of lauric acid, c 12 h 22 o 2 heating cooling time min temperaturec time min temperaturec. Her macaroons contain up to 7 grams of lauric acid per 2 ounces. Place the test tube of stearic acid or lauric acid in the hot water on the hot plate.
Lab report for water experiment linkedin slideshare. Using freezing point depression to find molecular weight advanced chemistry with vernier 4 3 time freezing point. This experiment could also be done using datalogging equipment lesson organisation. Adjust the temperature setting on the hot plate so that it remains below 55c. In addition, it has been reported that lauric acid, myristic acid, and linoleic acid had 100% inhibition at mic values of 25 gml, myristic acid and lauric acid showed 90% and 76% inhibition at 50 gml, and linoleic acid showed moderate antimicrobial activity at 50 gml against multidrugresistant mdr m. Coconut oil has grown in popularity as a nutritious oil that can be used to improve skin health and condition dry hair. But larger medicinal amounts should be avoided until more is known. Lab heating curves, cooling curves, lauric acid, themochemistry, latent heatthis lab will help your students examine the temperature changes undergone by a sample of matter during a phase change. Use a second temperature sensor to monitor the temperature of the water. Lauric acid dodecanoic acid latest price, manufacturers. What is the effect of increasing amount of substance on coolingheating curves. During the plateau, is heat being lost, added, or not involved.
Jul 25, 2017 health benefits of lauric acid in coconut oil. This paper deals with the thermal cycle tests of the binary mixtures based on fatty acids, i. Construct a heating and cooling curve of a pure substance using experimental data. Pdf thermal characterization of lauric acid and stearic.
Do not move the temperature sensors during the initial portion of the procedure. With a very slight up and down motion of the temperature probe, continuously stir the lauric acid during the cooling. When you are completely done collecting data for the day, the freezing temperature of the benzoic acid lauric acid. Sample data for the heating and cooling of lauric acid, c. Place all the boiling tubes with stearic acid into a large beaker. To determine the freezingmelting point of lauric acid from the coolingheating curves. Properties of lauric acid and their significance in coconut oil 2015 dayrit, fabian m. Ternary mixture of fatty acids as phase change materials for thermal. Figure 2 shows a dsc curve of pasa eutectic mixture. After removing the heat, the temperature was recorded at 10s intervals until the lauric acid completely solidified, approximately 4 hours.
Referring to the graph for the cooling curve, determine the freezing point temperature of the lauric acid. In this experiment a heating and cooling curve will be constructed to help determine the melting freezing points of lauric acid. Figure 2 shows a sample of paraffin wax paraffin, stearic acid fatty acid and sodium. Students can then use this curve to identify the meltingfreezing point of lauric acid. Properties of lauric acid and their significance in coconut oil.
Safety data sheet according to 29cfr19101200 and ghs rev. To generate heating and cooling curves for a pure substance. The subcooling curve of paraffin and 5 fatty acids under different mixing ratios. Myristic acid represents 11% of the dairy fatty acids and increase total cholesterol as much as palmitic acid, but does not affect total cholesterol. But i was a little confused by the plateau reigons that appeared in both curves. Pdf thermal characterization of lauric acid and stearic acid binary. Dec 20, 2015 heating curve of lauric acid tamara desso. It takes energy to break bonds, and making bonds releases energy. To understand that a phase change is a physical change. The flat part of the curve denotes the time interval when the lauric acid was freezing, or changing from liquid to solid. Nect gr 10 heating and cooling curve of water duration. A great alternative to the heating and cooling curves of water. Lauric acid c12 and coconut oil lauric acid, or dodecanoic acid, is a saturated fatty acid with the molecular formula ch3ch210cooh. To study the effects of heating and cooling a pure substance through a change of phase.
Measure the thermal characteristics heat capacity, latent heat of fusion, and melting temperature of stearic lauric acid mixtures using differential. These temperature changes are the increase or decrease in this substances kinetic energy. Payton lane 21716 3 rd period a heating and cooling curve for lauric acid background info. It is a white, powdery solid with a faint odor of bay oil. Feb 22, 2008 i drew lauric acid heating and cooling curves for a lab. Feb 04, 2020 sure the water level outside the test tube is higher than the lauric acid level inside the test tube. Lauric acid is a great choice for this lab because of its relatively high melting point. Determine the freezing point and melting point temperatures of a pure substance. You will use lauric acid in a school lab to make your own cooling curve. Preparation and thermal properties of lauric acidmyristyl alcohol as. Gently stir with the thermometer as you take data until the lauric acid starts to solidify.
The melting point of the laurel acid from the graph is 45 degrees celsius. Along with it being an excellent cooking oil due to its high heat point, this tropical plant oil contains one of the highest sources of a medium chain fatty acid called lauric acid. Obtain a ring stand, thermometer, and thermometer clamp. Request pdf experimental investigation on melting heat transfer characteristics. Lauric acid has a melting point of about 45c and is easily melted in a test tube placed in a beaker of hot water. Some research suggests lauric acid might be a safer fat than transfats in food preparations.