CHEM110L UCSC Study of Energy Chemistry Lab Report

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Nyzbevl

Science

CHEM110L

University of California Santa Cruz

Description

please read the attachments before writing the report.

Read the instructions that we followed for lab experiment to know the tools we used and the chemicals.

Also read the attached slides which is also about the three simple experiment we did, it will help.

Report sheets for the three experiments are attached which include all the data that we collected for this lab report.

Report Style: ( the lap reprt should include 1. Heat of solution of salt 2. Heat capacity of calorimeter 3. Heat capacity of a metal.) (report should include the three experiment)

1-Cover Page (50 points)

2-Introduction (50 points) (should include what is the lab about, how the report will cover the experiment. General information about the three simple experiment)

3- Typed data and observations (400 points) (should include all the data attached as report sheets with further information like what you think of the reactions and how we got these numbers. Also, pictures while doing the experiments will be attached)

4- What's Up (200 points) (how can we involve these three experiments in our daily life in engineering) ( a real life example for each one)

5-Conclusion (100 points) (explanation of the three experiments and what you learn from these experiments and what you think) (explosions of how you thing the data are, and explain what error occurred in the experiments if)

(More pictures will be attached for during the experiment)

(Example of the complete work will be attached)

(There will be a plagiarism check)

More information will be attached to write the report.

Unformatted Attachment Preview

15 Date Exp. No. Name Lab Partner Locker/ Desk No. Course & Section No. 5.00 g Sioo 45 mlig 50 25 C 18 °C ExperimenvSubject The ealme: vist at everyy 6 • O.S DA Heat of solution na salt Call , NH4 Cl a. Grams of sales -g g Ba Milliliter (grams) afuator in Cup 95 mLeg C. Grams of solution (20+2b) 50 32 18 -g d. Find the tampretmen Saution e. Initial Temperture of water °C 25°C Fo Temperature Change Z- C С go Totul Calories of haut Chergy cal cal elelveted evolved or ceh,somhed (show the calculation) h. Was the preess exothermic or exothermic endothrinic endotherimic? 1. Heat at solution per gram of salt (2g/2a); indicate (+) whether chsorbed (4) arte erdved --*--caly) cally .-Z- (-) 1. GA 3100 Witness/TA Date Date Signature Note: Insert Divider Under Copy Sheet Before Writing THE HAYDEN-MCNEIL STUDENT LAB NOTEBOOK 16 Date Lab Partner Locker/ Desk No. Course & Section No. Experiment Subject Het capacity of calorimeter Katana OA (Heat coperty of calorimeter) 50.0 ml of water at 65° is added to a calorimeter Cantanig 500mL of water at After wating for the system to equilibrate, The Firel Temp reach is 35 C Calculation the heat capacity of calorimeter ra that ra 35C - 65 C = -30C = 4.18 4 Jlgxi Sp-heat of water & At cold 35c-1°C 24 cl * 9 cold That masp- heat & At (50g) X(4-184J1gxC) x&#ZE)(-300) = -6276J (50g (4.184 J/gxC)( 24 ) = 50 20.83 By rearranging the g equation, qhot = -(qcold-qcal), * acal we solve for a cal * q hat - q cold 5020-8262767 - 6276J - 5020.8 +1255.2J Heat capacity of the calorimeter Ccal Renewper the calorimeter Includes the Im.Og of water So we must include the heat cepaty of the much water. Coal = 532 1255-23 +4.184 fly xCx100g 24°C 2 Date Witness/TA Date Signature Note: Insert Divider Under Copy Sheet Before Writing THE HAYDEN-MCNEIL STUDENT LAB NOTEBOOK Exp. No. Experiment/Subject Name Lab Partner Locker/ Desk No. Course & Section No. TE (from graph) Iso sea ((Heat capacity of Ajmetal) offen metal) (Time) Mass of metal g(9.8) 80 - 9 30 sec turtial T of metalqoc) 80 60 sec Maess of water (53.99, -180 ។ 90 sec Initial T of water 60 80 120 sec 20 - T change for water 8011 180 sec - Heat capacity of water (572) TO F-32 (a)=2 Heat gated by water (J) 4T =80-21.1=58.9 gained - Tchange for metall C) 80-90 = -10°C spesific heat of metal (J1g.) 4.184 3 GO Socha Date Witness/TA Date Signature Note: Insert Divider Under Copy Sheet Before Writing THE HAYDEN-MCNEIL STUDENT LAB NOTEBOOK EXPERIMENT #7: CALORIMETRY IN A COFFEE CUP Purpose: The purpose of this experiment is to measure, using a "coffee cup" calorimeter, the enthalpy of reaction for two acid-base reactions and show that Hess's Law of Heat Summation holds true, measure the enthalpy of dissolution for calcium chloride, and measure the heat capacity for a metal. Special Apparatus: 2 Styrofoam cups Plastic lid Thermometer Discussion: Chemical reactions and processes may produce or absorb heat when they occur. For example when methane (a major component of natural gas) burns, heat is produced. As you may guess, it is of major importance to the chemist whether heat is absorbed or produced 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. Heat is defined as the energy that flows into or out of a system. 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 water of solution. The standard SI unit for energy (and therefore heat) is the joule (J) and is defined as one Newton of force acting over the distance of one meter or: 1 Joule =(kg-m-/s2) Another commonly used unit of heat energy is the calorie (cal) which was originally defined as the amount of heat needed to raise the temperature of 1 gram of water by 1 degree Celsius. The calorie is now defined in terms of the joule: 1 calorie = 4.184joules (exact) When using calories be careful to distinguish between Calories with a capital C and calories with a small c. One food Calorie is equal to 1000 calories. When we examine the amount of heat produced or absorbed during a reaction we refer to the heat of reaction (enthalpy of reaction if the change in the system occurs at constant pressure). The heat of reaction is the amount of heat needed to return a system to a given temperature after the reaction is complete. A reaction that produces heat has a negative heat of reaction and is called exothermic and a reaction that absorbs heat has a positive heat of reaction and is called endothermic. In writing a thermochemical equation the enthalpy of reaction is written kJ per mole of equation and the physical states of the substances and amounts involved must be clearly stated. Enthalpies of reaction must be determined by experimental measurement or determined by using other known experimental values. 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"). For this experiment we will use a "coffee cup" calorimeter which consists of two nested polystyrene coffee cups and a thermometer. See diagram. 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. In our experiment the polystyrene coffee cups act as an insulated container to keep all heat energy in the solution in the cups. 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 Anange, 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: where q is the heat exchanged, C is the heat capacity, and delta T is the temperature change. Specific heat capacity values C, (heat capacity per gram) or molar heat capacity values Cm (heat capacity per mole) for a variety of substances can be found in standard handbooks, for example the CRC Handbook of Chemistry and Physics. Remember, when using specific heat or molar heat capacities you have to take into account how much of the material you have. EXPERIMENT #7: CALORIMETRY IN A COFFEE CUP Purpose: The purpose of this experiment is to measure, using a "coffee cup" calorimeter, the enthalpy of reaction for two acid-base reactions and show that Hess's Law of Heat Summation holds true, measure the enthalpy of dissolution for calcium chloride, and measure the heat capacity for a metal. Special Apparatus: 2 Styrofoam cups Plastic lid Thermometer Discussion: Chemical reactions and processes may produce or absorb heat when they occur. For example when methane (a major component of natural gas) burns, heat is produced. As you may guess, it is of major importance to the chemist whether heat is absorbed or produced 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. Heat is defined as the energy that flows into or out of a system. 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 water of solution. The standard SI unit for energy (and therefore heat) is the joule (J) and is defined as one Newton of force acting over the distance of one meter or: 1 Joule =(kg-m-/s2) Another commonly used unit of heat energy is the calorie (cal) which was originally defined as the amount of heat needed to raise the temperature of 1 gram of water by 1 degree Celsius. The calorie is now defined in terms of the joule: 1 calorie = 4.184joules (exact) When using calories be careful to distinguish between Calories with a capital C and calories with a small c. One food Calorie is equal to 1000 calories. When we examine the amount of heat produced or absorbed during a reaction we refer to the heat of reaction (enthalpy of reaction if the change in the system occurs at constant pressure). The heat of reaction is the amount of heat needed to return a system to a given temperature after the reaction is complete. A reaction that produces heat has a negative heat of reaction and is called exothermic and a reaction that absorbs heat has a positive heat of reaction and is called endothermic. In writing a thermochemical equation the enthalpy of reaction is written kJ per mole of equation and the physical states of the substances and amounts involved must be clearly stated. Enthalpies of reaction must be determined by experimental measurement or determined by using other known experimental values. 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"). For this experiment we will use a "coffee cup" calorimeter which consists of two nested polystyrene coffee cups and a thermometer. See diagram. 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. In our experiment the polystyrene coffee cups act as an insulated container to keep all heat energy in the solution in the cups. 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 Anange, 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: where q is the heat exchanged, C is the heat capacity, and delta T is the temperature change. Specific heat capacity values C, (heat capacity per gram) or molar heat capacity values Cm (heat capacity per mole) for a variety of substances can be found in standard handbooks, for example the CRC Handbook of Chemistry and Physics. Remember, when using specific heat or molar heat capacities you have to take into account how much of the material you have. Concept: The enthalpies of reaction for the reaction of HCl (aq) + NaOH (aq) and the reaction of HCl (aq) + NH3 (aq) will be determined and then used to check the validity of Hess's law by comparing the difference in their enthalpies of reaction to literature value for the enthalpy of reaction for NaOH (aq) + NH4Cl (aq). The heat of solution for CaCl2 will be determined by dissolving a known amount of CaCl, in a known amount of water and measuring the temperature change. Because the CaCl2 does not all dissolve immediately, we must measure the temperature over the period of a couple of minutes and extrapolate back to time zero see figure below. The heat capacity for a piece of metal will be determined by heating the piece of metal in a hot water bath and then quickly transferring it to a calorimeter containing a known amount of water. By determining the equilibrium temperature after the water and metal are in contact we can determine the heat capacity of the metal. Because the metal and water take a finite time to reach thermal equilibrium, we must measure the temperature over the period of a couple of minutes and extrapolate back to time zero. Procedure: NOTE: Record all temperature measurements to the nearest +0.1°C. Assemble the "coffee-cup" calorimeter according to the following figure. CAUTION: HCI, NaOH, and NH3 solutions can cause chemical burns. DISPOSAL: All solutions from this experiment may be safely disposed of down the sink with running water. Reaction of HCl and NaOH. Using a graduated cylinder, measure out 50.0 mL of the 2.0 M HCl solution into the calorimeter. Carefully rinse out the cylinder with distilled water, and measure out 50.0 mL of the 2.0 M NaOH solution. Check to make sure that the two solutions are with in +0.5°C of each other. Use the average temperature of the two solutions as your initial temperature, T;. 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 +0.5°C) put the thermometer in the HCl solution in the coffee cup 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. Determine the amount of heat produced in the reaction, assume that the solution has the same density and specific heat capacity as pure water: 1.00 g/mL and 4.184 J/(g °C). Calculate the heat of reaction per mole of H2O formed (Hint: If the HCl and NaOH are not the same concentration and you have equal volumes, the reagent with the lesser concentration will be limiting because of the 1:1 stoichiornetry). Reaction of HCl and NH3. Follow the same procedure as for HCl + NaOH, but substitute 2.0 M NHz for the NaOH. 3
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Explanation & Answer

Attached.

GENERAL ENGINEERING CHEMISTRY 1

NAME:

DETERMINATION OF HEAT
CAPACITIES
HEAT OF SOLUTION, HEAT CAPACITY OF CALORIMETER AND HEAT CAPACITY OF
A METAL

Introduction
Experiment 1: HEAT OF SOLUTION OF A SALT
The study of energy and how it is transformed in chemical reactions accompanied by physical
changes is referred to as thermochemistry. In such reactions, energy is released or absorbed in
the form of heat energy. The process in which heat is absorbed from the surrounding such
reaction can be described as an endothermic reaction whereas if heat is released the reaction is
said to be exothermic. Calorimetry is a technic used to measure the amount of heat released or
absorbed in calories or joules. When a salt is dissolved in water the amount of heat released or
absorbed is referred to as heat of solution this is given by
Quantity of heat=mass of water*specific heat capacity of water *change in temperature
Experiment 2: HEAT CAPACITY OF CALORIMETER
The amount of heat energy required to increase the temperature of a quantity by 10C is referred
to as heat capacity. A calorimeter is made in such a way that no heat energy of components in its
escape. To determine the heat capacity of a calorimeter experimentally equal amounts of hot and
cold water are mixed and the final equilibrium temperature is determined.
The assumption made is that the calorimeter absorbs no heat at all. In this case, the heat lost by
the hot water is the heat gained by the cold water
Heat lost by hot water = heat gained by cold water + heat gained by calorimeter
-q hot = q cold + q calorimeter
Therefore q calorimeter can be determ...


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