In this test, primary halides precipitate the fastest while secondary halides need to be heated in order for a reaction to occur. Comparison of the rates of precipitation of the obtained product to standard 1° and 2° bromide solutions will show whether the product is a primary or secondary
The substitution reaction was successful but not fully effective. 19. If the data was inconclusive, then comparing various compounds and the unknown based on physical characteristics would be the first step, titrations would also be a good method. 20. To get a better yield, redoing the experiment would require careful attention in the recrystallization steps: amount of solvent used, how hot solvent is, if the mixture cools to room temperature before placing it in an ice
Verna Wang Hannah Palmer CHEM 101-069 Lab 11-19-16 Stoichiometry and Limiting Reagents Lab Report Purpose: We are using the reaction of sodium hydroxide and calcium chloride to illustrate stoichiometry by demonstrating proportions needed to cause a reaction to take place. Background: Just like a recipe would call for a specific amount of one ingredient to a specific amount of another, stoichiometry is the same exact method for calculating moles in a chemical reaction. Sometimes, we may not have enough of or too much of one ingredient , which would be defined as limiting and excess reagent, respectively.
Although .7906 mg of phosphonium salt was added, this probably was not enough to complete the reaction. The only significant change throughout method was 1 was that the yellowish mixture became slightly lighter. However, it was found that after vacuum filtration, there was some white and yellow
Effect of temperature on the reaction between the catalase and H2O2 Figure 1 shows that the optimum temperature for catalase to catalyze hydrogen peroxide is around room temperature (30℃) as it has a very fast reaction rate. The overall trend is that temperatures different from 30℃, will make the reaction rate decrease. Discussion This experiment supported the hypothesis, since catalase was the most effective with hydrogen peroxide when it was in an environment with a temperature of 30℃. It was expected that an extreme temperature would decrease the rate of reaction and results observed support that idea.
The enthalpy of dissolution for potassium chloride came out to be 8.73 kJ/mol, which indicates that the process was endothermic. Since the dissociation of potassium chloride is endothermic, it requires heat to dissolve, which makes it a low preforming deicer in very cold temperatures. Potassium chloride costs $8.99 per lb and compared to the lowest cost deicer sodium chloride, which costs $2.09 per lb, potassium chloride was not cost efficient. The environmental impacts are due to the chlorine component of each deicer. There are various negative health effects induced by chlorine that appear in animals and organisms in water and soil environments.
PChem Experiment No. 3 Cryoscopic determination of molecular weight 1. Aims To determine the apparent molecular weight of benzoic acid in cyclohexane by creating a binary system and finding the different freezing points of the solutions. 3. Experimental Procedure A dry, empty freezing-point tube and its cork were weighed together.
The gas particles collide with each other and the wall of container with higher frequency and this will exert a higher pressure. The kinetic energy remains the same and temperature remains constant. Charles’ Law ( Law of Volume ) reveals that when pressure is kept constant, the volume of gas is directly proportional to the temperature of the gas in kelvin. Relating this back to molar volume, the higher the temperature, the higher the volume the gas occupies. When a certain amount of gas is heated to a higher temperature, the gas particles will have higher kinetic energy.
In the remaining 8 cases, the average cooling rate was -0.060C/min, which was in agreement with that reported by Khogali. However, another similar study performed by DSO in 2002, testing 22 male subjects, revealed an even greater cooling rate of 0.100C/min using the BCU . Ice water immersion was also found to be extremely effective in reducing the rectal temperature in humans. Costrini reported a high success rate in reducing the rectal temperature of heat-stroke casualties at a rate of 0.150C/min by immersing them in a large tub of ice water until rectal temperature was reduced to 39.00C
The acid region is the curve on the left of the graph, whereas the base region is on the left. When HCl was added to both buffer, the pH of the buffer decrease. Ideally, the designed buffer can maintain the pH at 1 units: in this case between 3 to 5. Once the pH surpassed these change, the change in volume and pH will be drastic.