Che 134 Lab Manual
Che 134 lab manual Wed 30 Aug, 2017 1/1 che 134 lab manual che 134 lab manual Stony Brook Undergraduate Bulletin - Fall 2018 – Spring. PHY 112: Light, Color, and Vision.
Reference:; 1;;;;. European history study guide key. The Placentia-Yorba Linda Unified School District prohibits discrimination, harassment, intimidation, and bullying in all district activities, programs, and employment based upon actual or perceived gender, gender identity, gender expression, race, ethnicity, color, religion, ancestry, nationality, national origin, ethnic group identification, sex, sexual orientation, marital or parental status, pregnancy, age, physical or mental disability or on the basis of a person’s association with a person or group with one or more of these actual or perceived characteristics.
Part A: Observation of Solubility Properties During the first part of our lab, I used test tubes to test the solubility of benzil, benzoic acid,cinnamic acid, and urea in the following solvents: ligroin, ethyl acetate, 95% ethyl alcohol, and water. I mixed the contents of each test tube, and recorded solubility. I then added a boiling stone to each test tube with undissolved solid and heated gently in a hot water bath. If the solid dissolved, I then plunged the test tube into a ice bath to test whether crystals or a precipitate formed. Boiling Stones Purpose: Boiling stones (or sticks) are used to help solutions boil calmly and predictably. They are generally made of non-porous materials and often have a non-reactive coating of PTFE (polytetraflouroethylene). They function by providing nucleation sites, which is an extremely localized budding of a distinct thermodynamic phase.
If a solution is heated rapidly (becomes superheated) without a nucleation site, it might form a large vapor bubble when it finally boils, which will then violently expel the solution from the contain er. This is called 'bumping'. This phenomenom is also why everyone should appreciate and love boiling stones. Based on the results of the solubility tests, I was able to determine suitable crystallization solvents or solvent pairs for each solute. A solvent pair consists of two miscible (meaning that they form a homogeneous mixture when added together) solvents in which the solute will be very soluble in one, and insoluble in the other. Part B: Crystallization of Benzoic Acid from Ligroin First, I placed a small amount of benzoic acid in a large test tube and added enough ligroin to cover the solute.
I then added a boling stone and placed in a hot water bath, adding small amounts of ligroin until the benzoic acid dissolved. Once the benzoic acid had dissolved, I was left with a 'saturated solution'. In order to demonstrate a poor crystallization technique to myself (as per the lab manual directions), I then plunged the test tube into a ice bath, shaking the test tube constantly. In order to repeat the experiment with the proper technique, I then reheated the solution in a hot water bath until the solid dissolved again. I then cooled the solution, undisturbed, to room temperature. After the solution cooled, I placed the test tube in a ice bath while cooling a small amount of ligroin.
At this point, crystals had formed on the bottom of my test tube. I used a pipette to remove the supernatant solution (the liquid remaining after a crystallization), then added (and consequently removed) a small portion of the ligroin I had chilled to wash the benzoic acid crystals. Part C: Crystallization of Benzoic Acid from Water with Removal of Observable Purities I first measured out and placed bezoic acid into a small Erlenmeyer flask.
Erlenmeyer Flask I then added water and heated on a hot plate. At this time, I also preheated about 20 mL of water on the hot plate as well. I then set up an apparatus for hot filtration, shown below. The purpose of the hot filtration apparatus was to filter out the insoluble impurities from the dissolved benzoic acid. Before filtering the solution, I added a few more mLs of water to the dissolved benzoic acid because I wanted to prevent the benzoic acid from crystallizing as the water evaporated. If the benzoic acid crystallized before it had been filtered, it would be left behind on the filter paper with the impurities and I would have ended this experiment with a low yield. After filtering, I allowed the solution to cool slowly and undisturbed to room temperature before placing in an ice-water bath.
Physics Lab Manual
I'm a new transfer student and im taking CHE 134 lab here at stony brook. I'm confused with the policy they have here, like is it really every other week for lab. I noticed that the pre lab questions are individualzed.
Do TA's actually check them and where do you learn how to solve the pre lab because it looks difficult. Is it a textbook, or the lecture.
Nursing Lab Manual
Are the virtual labs hard, do they take off points. How long do these pre lab and virtual lab things take- is it few mins or couple hours. When you go to lab, are all of the labs 3 hours long or can you leave early. Whats the best way to prepare for your lab, read the stuff, watch the videso??