Introduction According to the Columbia Encyclopedia, sodium tetraborate decahydrate (also known as borax) is a chemical compound that is slightly soluble in cold water but very soluble in hot water (“Borax”). Some of the various uses of borax are a cleansing agent, an antiseptic, occasionally as a preservative and used as a flux for silver soldering. The purpose of the experiment was to determine the thermodynamic quantities, enthalpy (ΔH°) and the standardized entropy (ΔS°) of the solvation of sodium tetraborate decahydrate, borax, in water. This was achieved by observing the effect various temperatures have on the solubility product of borax.
Experimental Details The experiment required that a 250 mL beaker be filled with 75-85 mL of distilled water. Then between 25-30 grams of borax was weighed out using the electric analytical balance and added into the beaker of distilled water. To ensure that all of the borax was transferred from the weigh boat, it was washed with distilled water a few times and also added into the beaker. The beaker
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From the results, it is concluded that as the temperature increased the solubility product increased as well. The high percent errors could account for the following errors: there could have been solution residue left in the glass wear from the previous class’s experimentation resulting in cross contamination, misjudgment of the color change once the solution was reaching the end-point, adding too many drops of bromocresol green indicator, and because the borax was a solid some of the 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
First, 100 mL of regular deionized water was measured using a 100 mL graduated cylinder. This water was then poured into the styrofoam cup that will be used to gather the hot water later. The water level was then marked using a pen on the inside of the cup. The water was then dumped out, and the cup was dried. Next, 100 mL of regular deionized water was measured using a 100 mL graduated cylinder, and the fish tank thermometer was placed in the water. Once the temperature was stabilizing in the graduated cylinder, the marked styrofoam cup was filled to the mark with hot water. Quickly, the temperature of the regular water was recorded immediately before it was poured into the styrofoam cup. The regular/hot water was mixed for a couple seconds, and the fish tank thermometer was then submerged into the water. After approximately 30 seconds, the temperature of the mixture leveled out, and was recorded. This was repeated three
The procedure of the lab on day one was to get a ring stand and clamp, then put the substance in the test tube. Then put the test tube in the clamp and then get a Bunsen burner. After that put the Bunsen burner underneath the test tube to heat it. The procedure of the lab for day two was almost exactly the same, except the substances that were used were different. The
Firstly, an amount of 40.90 g of NaCl was weighed using electronic balance (Adventurer™, Ohaus) and later was placed in a 500 ml beaker. Then, 6.05 g of Tris base, followed by 10.00 g of CTAB and 3.70 g of EDTA were added into the beaker. After that, 400 ml of sterilized distilled water, sdH2O was poured into the beaker to dissolve the substances. Then, the solution was stirred using the magnetic stirrer until the solution become crystal clear for about 3 hours on a hotplate stirrer (Lab Tech® LMS-1003). After the solution become clear, it was cool down to room temperature. Later, the solution was poured into 500 ml sterilized bottle. The bottle then was fully wrapped with aluminium foil to avoid from light. Next, 1 mL of 2-mercaptoethanol-β-mercapto was added into fully covered bottle. Lastly, the volume of the solution in the bottle was added with sdH2O until it reaches 500 ml. The bottle was labelled accordingly and was stored on chemical working bench.
On the lid of the calorimeter, there were two holes and one was being used for the thermometer, and the second one was left open. This hole could have let heat to escape as the reaction was taking place which would have lowered the final temperature value. These conditions would have led to a lower final temperature value. To prevent even the slightest anomalies in the future, any holes on the calorimeter can be covered by tape or another item that could block the passage. The top of the calorimeter could also be covered with aluminum and this would not only cover the holes but would secure the space under the lid so any heat that may escape would stay within the area due to the aluminum. Aluminum could also be tucked in the space between the lid and the calorimeter to once again lock the heat in. This way, the calorimeter will be more effective and maintain all the heat of the reaction resulting in values that are completely accurate and decreasing even the slightest
Planning Firstly here is a list of equipment I used. Boiling tubes Weighing scales Knife Paper towels 100% solution 0% solution (distilled water) measuring beakers potato chips Cork borer. We planned to start our experiment by doing some preliminary work. We planned to set up our experiment in the following way.
the water baths I think were accurate enough but having two thermometers in each bath maybe would have helped to hold the temperature readings more accurately. We were not given any instructions either to shake or not to shake the test tubes with the coloured solutions before inserting them in the spectrophotometer to read the absorbance. By shaking each test tube a certain number of times before putting it in the spectrophotometer could have improved the accuracy of the absorbance of the solutions.
Paragraph 2: It is believed that as the temperature of the water increases the time it will take for the tablet to dissolve will decrease. This is believed since the temperature there will be more energy allowing the particles to get together and form a reaction allowing the ta...
* It was almost impossible to tell when the Alka-Seltzer tablet had dissolved, each time the experiment was done. This was a huge problem for the experiment as this could have totally caused problems to the experiment. A special type of detector apparatus, which bleeped when the correct amount of Alka-Seltzer tablet dissolved, could improve this, each time the experiment was done.
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.
Borax, another one of slimes key ingredient! Borax is an important boron compound. Borax is made from composites from seasonal lakes. Borax is a made of little white crystals. Borax isn't only used for Slime. Borax is a detergent booster. So Borax is not safe for everybody, it will have different symptoms to different
If the temperature had been increased in batches of 5oC it would have provided a greater range of results to work with, which would create a high level of data to work with when compiling the mean and plotting the graphs as evidence.
It could have been lower than 100% because some product was lost during the recrystallization process, or due to an incorrect separation of the impurities when cooling the mixtures. The melting point data confirmed that the synthesized crystals were likely identical to the methoxybenzyl phenol ether because the mixed melting point was the same as the purified crystals. If the products were different or the synthesized product had to many impurities in it then the mixed melting point would have been lower than that of just the crystals, by themselves. The TLC made sense, after looking at the TLC plates under UV light and the calculation of the Rf values, it was confirmed that the 4- Methoxy-phenol was present in the unknown.
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.
A lot of society travel to exotic lands because they want to see and experience the different cultures as well as get away from stress and everyday life. Today, many people travel to this exotic island, Bora Bora, to relax on the magnificent white beaches and to stay in the admirable huts that are on the crystal clear waters. According to the U.S Travel Association, about 2.2 billion Americans took a vacation in 2016 seeking for the thrill and experience of exploring new things (Irimia and Gottschling ).
borate) and 1.0 g. of sodium hydroxide in 20 mL of warm water. It may