Thermochemistry Lab Hypothesis We predict that two different physical changes (dissolving of a chemical substance in water) will produce energy changes; one exothermic and one endothermic. We predict that the temperature change will be affected by the change in system (open vs. closed) will be as follows: the temperature change in the closed system will be greater than that of the open system. Materials Refer to attached sheet Method Refer to attached sheet Observations Substance Added
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1 106 M-2 and a G° of -34.2 kJ/mol. If the concentrations of A‚ B‚ and C are all 1.0 mM and the temperature is 25 °C‚ a. b. c. d. e. the G for the reaction is negative and the reaction will proceed from left to right. the G for the reaction is positive and the reaction will proceed from right to left. the G for the reaction is zero and the reaction is at equilibrium. the G = G° and lnQ = 0. The G = lnQ and G° = 0. 4. For the reaction A B‚ G°’ = –60 kJ/mol. The reaction is started with
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General Issues: As with most FRQs the biggest issues were typically – - lack of enough outside info - time management issues and lack of development‚ - failure to completely focus on the prompt and keeping your evidence in the context of developing a clear argument that clearly answers the question. 2006 B: For whom and to what extent was the American West a land of opportunity from 1865 to 1890? For Whom? Homesteaders via 1862 Homestead Act Farmers Miners and prospectors Loggers Buffalo
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force called hydrogen bonding. This bonding is then replaced by ion-dipole when salt is dissolved in the water which is a weaker intermolecular force compared to hydrogen bonding. "Generally speaking‚ Hydrogen bonding is stronger (20-40 KJ/mol) than ion-dipole (10-20 KJ/mol)" ("Chemicalforums") . The water is then not held together as tightly and less force is needed to separate one drop from the main body of water. It would therefore be expected that the volume of the drop would be less as the gravitational
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Materials 1 spectroscope 1 incandescent bulb 1 hydrogen gas discharge tube 1 mercury discharge tube 1 nitrogen gas discharge tube 1 fluorescent light 1 neon gas discharge tube Solar light source 1 discharge tube apparatus Procedure The procedure of using a spectroscope was practiced with a fluorescent light source. The slit was pointed towards the source‚ and the spectroscope was shifted until the spectrum was clearly visible. The appearance of the spectrum from the fluorescent light
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of a Rate Constant By Marvin Coleman March 7‚ 2011 Abstract: From the shown calculations & graphical analysis‚ the experimentally determined rate law is rate = K[I-].969 [H2O2].991 and the experimentally determined activation energy is 59.50 kJ/mole. Introduction: The rate of a reaction varies at different temperatures and reactant concentrations. In this experiment‚ the orders and dependence of the rate constant of the products used are determined by the following chemical reaction:
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safety goggles‚ gloves and lab coats. 2. Set up retort stand on the heat mat‚ and attach the boss head clamp. 3. Fill test tube with 7mL water and place in the clamp 4. Record the mass of the teddy bear and the energy in the teddy bear (per 100g and in KJ) 5. Put teddy on the miniature stand‚ and adjust the boss head clamp so that the test tube is 1cm away from the tiny teddy 6. Measure the temperature of the water using the thermometer and record the results 7. Light the tiny teddy using matches until
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First Law of Thermodynamics The first law of thermodynamics states that the energy cannot be created nor destroyed it can only be changed from one form to another. Another name for this law is the law of conservation of energy. This means that the total energy of a system plus its surroundings is constant and does not change. Energy can‚ however‚ be transferred in or out of the system and to or from the surroundings through work or heat. Conservation of Energy Energy may be defined as the
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which states that W ∝ H or W = J H The conversion factor between electric energy measured in joules and heat energy in calories is called the electrical equivalent of heat 1 cal(calorie) = 4.186J (joules) or Kj =4.186J/cal In this particular experiment we will reexamine the value of Kj. Other basic SI units involved in this experiment are: Coulomb ( c) : unit for electric charge Ampere(A) unit for electric current‚ flow rate of charge‚ A=C/s Volt(V) unit for electric potential‚ energy/coulomb
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EXERCISE 6 1. A shopper in a supermarket pushes a cart with a force of 35 N directed at an angle of 25° downward from the horizontal. Find the work done by the shopper as she moves down a 50-m length of aisle. 1.6 kJ 2. A horizontal force of 150 N is used to push a 40.0-kg packing crate a distance of 6.00 m on a rough horizontal surface. If the crate moves at constant speed‚ find (a) the work done by the 150-N force and (b) the coefficient of kinetic friction between the crate and surface. 900J
Free Force Friction