Materials: 3 beakers Thermometer 3 Alka-Seltzer tablets Stopwatch Mortar and pestle Source of hot water Ice cubes Graph paper Procedures: Hot water- Run water from the hot tap until it is hot as possible Fill beaker with 80 mL of hot water Use thermometer to take temperature of water. Record in data table. Remove 1 Alka-Seltzer tablet from package Drop into the water. Measure the time it takes for the tablet to completely dissolve. BE READY WITH THE STOPWATCH.
Set min temperature to 15-18C c. Time should range from 0-250 seconds 7. Press DISPLAY to accept all values 8. Heat up 200mL of water in a microwave for about two minutes 9. Place hot water on a hot plate to keep warm 10. Nest one Styrofoam cup in another 11.
He placed the his temperature scale at o degree for the boiling point, and ent downward and placed the freezing point at 100 degrees 10. What did the physicist Amonton contribute to the understanding of hot and cold? Amonton was doing heating, and cooling experiments. He saw that when he cooled the object that when the temp dropped so did the pressure. So he thought what would happen if you kept pushing the pressure back.
Data: Data Table 1 | | | Rubbing Alcohol Trial # | Boiling Point | Percent Error | 1 | 79.5 C | 3.52% | 2 | 84.0 C | 1.90% | 3 | 83.5 C | 1.30% | Data Table 2 | | | | Acetamide Trial # | Melting Point | Freezing Point | Percent Error (Melting Point) | 1 | 79.5 C | 57.5 C | 3.50% | 2 | 80.5 C | 59.5 C | 0.60% | 3 | 78.0 C | 61.0 C | 3.70% | Observations: It was observed that thermometer placement could affect the readings in the water bath. I ended up holding the test tube assembly to where the bottom of the test tube was not touching the bottom of the beaker to ensure better readings. Also, when substances recrystallize, I am not sure whether to take a reading when the substance has full crystallized or begun to so results could be fairly inaccurate. Questions: A. Why is it useful
Lab 4: Determination of Percent by Mass of the Composition in a Mixture by Gravimetric Analysis Introduction Thermal gravimetric analysis is used to determine the percent by mass is used to determine the percent by mass of a component in a mixture. When a mixture is heated to an appropriately high temperature, one component in the mixture decomposes to form a gaseous compound. The mass of this particular component is related to the mass of the gaseous compound. In this experiment, the percent by mass of sodium hydrogen carbonate (NaHCO3) and potassium chloride (KCl) in a mixture will be determined. Experimental First, we weighed 2 samples, each has 1 gram of NaHCO3-KCl mixture Second, we put the samples in 2 crucibles (A and B) and weighed them.
The manufacturing of these little soldiers for athletes relies on the principles of thermochemistry. The mixture of ammonium nitrate and water relies on endothermic properties or in this case when heat is absorbed to create the cold sensation in an ice pack. A device used to measure the quantity of heat transferred to or from an object is called a calorimeter. In most science labs it is more commonly referred to as a Styrofoam cup or a coffee cup calorimeter. In our lab we use a more sophisticated one which included a lid on the cup with an inserted thermometer and a stirrer.
Abstract The focus of this experiment was to analyze the kinetics of a nucleophilic substitution. A mixture of 0.3622-M 1-bromopropane and 0.3622-M potassium hydroxide in an 90:10 ethanol/water solvent provided the reactants for a SN2 reaction to occur in a temperature controlled bath at 50.0˚C. The disappearing reactant was found by titrating timed aliquots during the reaction and then measuring the concentration of hydroxide. The k-value was found to be 0.0202 M-1Min-1. Using the linear form of the Arrhenius equation the activation energy was calculated to be 19.9 kcal/mol.
Set the stopwatch to 1 minute. Use a lighter to light the fuel. Blow out the fire when the timer reaches 1 minute. Measure the final temperature of the water using a thermometer. Then measure the final mass of the fuel using a mass scale.
Add 1 mL of deionized water to the small test tube containing the precipitate and mix it and centrifuge it for 60 seconds. Then, add the supernatant into the boiling test tube and repeat this step one more time with another 1 mL of deionized water. Acquire a pair of metal test tube holders and heat the boiling test tube to evaporate the water for 15 minutes. Let is cool after and weigh it. Then, calculate a percent yield of zinc iodide and write a balanced chemical equation and determine the limiting
baking soda) will be mixed with acetic acid (HC2H3O2, a.k.a. vinegar) to generate sodium acetate (NaC2H3O2) and carbonic acid (H2CO3). The carbonic acid will rapidly decompose to generate gaseous carbon dioxide and liquid water. You will calculate your theoretical yield of NaC2H3O2 For this reaction, we will need to use 0.025 moles of NaHCO3. Procedure: 1.