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Freezing point depression lab
Freezing point depression lab
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Our objective was to pick the best chemical to be used in a hand warm. This chemical had to be cheap, relatively safe, and must raise the temperature by 20oC and no more. We add 6 different chemicals to water we record the inshell temperature and then add one a the 6 chemicals to the water and record the temperature change of the water. We also add cold water hot water together to find how much heat would escape the calorimeter. We found that the calorimeter absorbed 71.1J/oC. Then this information to calculate the energy that was released by all of the chemical reaction.
The dehydration of 2-methylcyclohexanol takes place at the bottom of the Hickman still. As the Hickman still heats up within the sand bath, the products evaporate and travel higher up in the still where they condense into a liquid and fall within the collection ring, thus separating the product from the remaining water. Drierite (CaSO4) is also added as a drying agent to absorb any leftover water within the product. The purity of the product will then be analyzed with infrared spectroscopy, paying attention to OH peak if it is present. Chemical Reactions: Data and Observations: Material Volume Mol.
The maximum depression of the freezing point of the com the blood.[2] With the formula below, freezing-point depression can be used to measure the degree of dissociation or the molar mass of the solute. This kind of
The next test used the test tubes labelled “cold” and , one again using a piece of liver and five milliliters of hydrogen peroxide with both being placed in the ice bath, both held vertical with a test tube clamp. After five minutes were up using a timer, the two tests were conducted. The test involving the boiling water had five milliliters of hydrogen peroxide poured into it. Meanwhile, the five milliliters of hydrogen peroxide was poured into the test tube labelled “cold”. After both tests, explanations were made about the
I. Purpose: To experimentally determine the mass and the mole content of a measured sample. II. Materials: The materials used in this experiment a 50-mL beaker, 12 samples, a balance and paper towels. III.
RESULTS & DISCUSSION The reaction scheme for the oxidation of cyclohexene to adipic acid is shown in Figure 2. This reaction was an ionic addition reaction, and it utilized the oxidizing properties of H2O2 in the presence of WO42-. For this reaction to occur, first Na2WO4 dissociated in the aqueous layer due to its ionic properties and the polarity of water as the solvent. WO42-, a complex stabilized by its resonance contributors, was taken into the organic layer by Aliquat 336, the phase transfer catalyst.
Research question What is the effect of temperature Amylase activity? Word count-1453 Background research Enzymes are biological catalysts that speed up a chemical reactions. They do this by decreasing the activation energy(the energy needed to start the reaction) of a chemical reaction. The enzyme present in our saliva is called Amylase. Amylase increases the rate of reaction by decreasing the activation energy needed to hydrolyse the starch molecules.
In this experiment, the amount of water lost in the 0.99 gram sample of hydrated salt was 0.35 grams, meaning that 35.4% of the salt’s mass was water. The unknown salt’s percent water is closest to that of Copper (II) Sulfate Pentahydrate, or CuSO4 ⋅ 5H2O. The percent error from the accepted percent water in CuSO4 ⋅ 5H2O is 1.67%, since the calculated value came out to be 0.6 less than the accepted value of 36.0%.This lab may have had some issues or sources of error, including the possibility of insufficient heating, meaning that some water may not have evaporated, that the scale was uncalibrated, or that the evaporating dish was still hot while being measured. This would have resulted in convection currents pushing up on the plate and making it seem lighter by lifting it up
The mixture was then distilled. When the temperature was reached to about 59℃, half vial of distillate (1V) and 1 mL of the liquid residue (1L) were collected. For 61.0℃, the distillation was then continued. Samples (2V, 2L) were taken at about 61.0℃.
Test of the hypothesis and data collection: Place two containers of equal amounts of water, one with sugar added, into the freezer.
The fractions in the fractional distillation such as N-hexane, isohexane, methyl cyclopentane have normal boiling point close to cyclohexane which makes the recovery of cyclohexane uneconomic and difficult. 2. Quantity of cyclohexane recovered is not enough to meet the current demand since the cyclohexane content of naphtha is about 5%- 15% by weight .3 Selection of Pathway to Cyclohexane (2) Hydrogenation of Benzene: C6H6 +3H2 →
In relation to a previous experiment in which the students determined the boiling points of two liquids, it was deduced that the boiling point of [propyl and methyl] alcohol was estimated to be around 80oC. According to numerous sources, ethanol boils (and consequently evaporates) at around 78.5oC[7] a much lower temperature compared to the alcoholic beverage’s other ingredients—water, for example, boils at precisely 100oC. It is immensely possible that because of this, ethanol is isolated from the beverage sooner than said beverage’s other components. Perhaps, if the students worked within
Aim: To find out the relationship between the greater concentration of sodium thiosulfate when mixed with hydrochloric acid and the time it takes for the reaction (the time it takes for the solution to turn cloudy) to take place and to show the effect on the rate of reaction when the concentration of one of the reactants change. Introduction: The theory of this experiment is that sodium thiosulfate and hydrochloric acid reach together to produce sulfur as one of its products. Sulfur is a yellow precipitate so, the solution will turn to yellow color while the reaction is occurring and it will continue until it will slowly turn completely opaque. The reaction of the experiment happens with this formula: “Na2 S2 O3 + HCL =
The aim of this experiment was to determine the specific heat of fusion for the change of phase from ice to water. A method based on the principle of energy conservation was used in the experiment. Simply, the ice absorbs heat that is equal to that lost by the stirrer, calorimeter, and water. Initially, the ice undergoes a change of phase from solid to liquid (melting point). The experiment was conducted by maintaining all the pieces of ice in a funnel until when the pieces would be used to drain off all the water.
Introduction Solubility is a chemical property that is measured in terms of the maximum amount of solute dissolved in a solvent at equilibrium. The resulting solution is called saturated solution. For example when a sample of sodium chloride solution in water is heated the behavior of the reaction is endothermic obstructing exothermic behavior. Another relationship that can be said about solubility is that the solubility of a solid substance increases as the temperature increases. The solubility of solutes is dependent on temperature.