Morgan State University Calorimetry Experiment Chemistry Lab 6

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Part 2 Exp. No Experiment/Subject Name se 12 Date Lab Partner Locker/ Desk No. HCL Course & Section No. = 23.5 Maolt=g s7 F 82 Å after Mixing at Inities weiter I= 820P Finel! Tothof AT: lo.sf I min 37 2min=361 36f 1 sw - 33 3 1 1 С. - HEI :221 Nadtt =201 Date Signature Witness/TA Date DEN-MCNEIL STUDENT IAR NOTEBOOK Note: Insert Divider Under Copy Sheet Before Writing EXPERIMENT #6: CALORIMETRY Project: A new eco-friendly coffee shop has just moved across from campus and is scheduled to open in three weeks. They had a great idea to use only glass containers for their hot coffee drinks. However, they were concerned about these containers' ability to keep the drinks hot. They decided to hire your consulting team to conduct some experiments to determine if their idea is so great! Your knowledge of calorimetry will prove to be invaluable. 1. Design and determine the best apparatus for use as a calorimeter 2. Use this apparatus to determine the heat of reaction of a chemical reaction Background: Chemical reactions and processes may produce or absorb heat when they occur. It is of major importance to the chemist whether heat is absorbed (endothermic) or produced (exothermic) by a particular reaction and how much heat is produced or absorbed for a given amount of material. The study of heat transfer during chemical reactions is called thermochemistry. Typically we are examining reactions occurring open to the atmosphere and therefore at a constant pressure); we refer to the heat exchanged at constant pressure as the change in enthalpy, delta H. Thermodynamically, the system is defined as the substance or substances that we are studying in which a change occurs. For chemical reactions, the system is generally the chemicals involved in the reaction. The system is in contrast with the surroundings which is everything else in the neighborhood of the system; this includes the water used as the solvent. To determine experimentally the amount of heat absorbed or produced during a chemical reaction, we use a device called a calorimeter (meter = "to measure" and calori = "calories"). We determine the amount of heat exchanged in a process by measuring changes in temperature for the immediate surroundings which are insulated from the rest of the universe. Because the cups are open to the atmosphere, any reaction carried out in the cups is done at constant pressure and the amount of heat exchanged will be the enthalpy change, delta H. In order to determine how much heat is exchanged based on a temperature change, we must also know the heat capacity of the material for which we are measuring the change in temperature. The amount of heat exchanged is equal to the heat capacity of the material times the change in temperature: q = CX ΔΤ. Techniques: Laboratory: measuring mass and volume, recording temperature Computer: apparatus setup using ChemSketch (do not cut and paste from this document), excel for data table and graphing 54 H outside of the test tube (careful; it is hot), and transfer the piece of metal into the calorimeter containing 50 mL of water without splashing any water out of the calorimeter. Measure the temperature at 30 second intervals for 3 minutes. What is the system? What is the surroundings? Analysis of experiment using chemistry drawing software. Draw the calorimeter after the metal has been added using the chemistry drawing software; include the compounds in the calorimeter. What is the system? What is the surroundings? metal Analysis of the metal through calculations. From your experimental data, the amount of heat gained by the water for the entire process (not for each temperature increment) can be calculated for each apparatus. If this is the heat gained by the water, what is heat loss by the metal? Using Excel, plot temperature vs. time. From this graph, you will gain information that will either support or refute your previous decision regarding the appropriateness of each designed apparatus. Calculate the heat capacity of metal from its heat loss for each apparatus. You will be given the known value of the heat capacity for your unknown metal once you have completed your calculations. Compare this value with your values determined experimentally and discuss. This should be the final data that will assist in determining the most appropriate calorimeter for use in a chemical reaction. Use of the designed calorimeter to determine the heat of reaction of a neutralization reaction. Add 50.0 mL of 2.0 M HCl solution into the calorimeter. Carefully rinse out your measuring tool with distilled water, and measure out 50.0 mL of 2.0 M NaOH solution. Check to make sure that the two solutions are within 20.5°C of each other. Use the average temperature of the two solutions as your initial temperature, Ti. Be sure to carefully rinse and wipe off the thermometer between measurements to avoid pre-mixing the solutions. Once the solutions are at the same temperature (within 10.5°C) put the thermometer in the HCl solution in the calorimeter and quickly add the NaOH solution. Use the thermometer to gently stir the resulting solution and measure the maximum temperature that is achieved; this is Tf. What is the system? What is the surroundings? 56 EXPERIMENT #6: CALORIMETRY Group Experimental Design Pre-lab 1. Design two unique calorimeters. The calorimeters will be judged on originality (no coffee cup calorimeters from online will get you the prize!), creativity, potential effectiveness, and how well it addresses the concerns of the coffee shop in your project. Some items available are: styrofoam cups, beakers (many sizes), aluminum foil and whatever else in the lab your instructor approves! 2. Write a detailed experimental procedure. This procedure should be written stepwise with the initials of the student who is performing that step in the procedure. Here is an example: 1. Weigh substance- AW (these are the initials of student performing task) 2. Get the volume of substance - EE 3. etc. Somos 59
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Inorganic Contaminants Present in a Sample of Water


I. Introduction
The test for the presence of inorganic contaminants present in a water sample is
a very important and practical laboratory procedure. A very practical application of
testing the presence of inorganic salts in a water sample is on the quality assurance of
drinking water. Since water is a vital to life, it is considered very important to consider
and assure water quality especially after treatment. The contaminants in a water sample
can be tested through two general methods: quantitative and qualitative tests.
The different tests that allow for the characterization of the inorganic salts present
in a water sample include pH testing, solubility test, conductivity test, flame test,
precipitation test with Silver nitrate and Barium chloride and gravimetric analysis. The
pH of the water sample will give an idea on the presence of minerals that are in a water
sample. The solubility test on the other hand will characterize the salts present in a
water sample since the solubility of most inorganic compounds with water is known.
With conductivity test, the number of ions that are in the water sample can be estimated.
The flame test on the other hand will determine what the specific compound is through
the emission of a distinct color. Reaction with Silver nitrate would form a solid
compound if there is an anion present. Depending on the color of the precipitate, the
identity of the anion can now be possibly determined. Finally, gravimetric analysis will
identify the amount of the sample present in the water sample
These tests were done in the experiment with a known sample (salt). These were
done to assess the accuracy of the said methods. Knowing the exact sample, it was then
possible to compare the results obtained with the qualitative and q...

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