Hess’ Law of Heat Summation Hess’ Law states that: "The enthalpy change for any reaction depends on the products and reactants and is independent of the pathway or the number of steps between the reactant and product". BASICALLY: Hess’ Law states "the heat evolved or absorbed in a chemical process is the same whether the process takes place in one or in several steps" >This is also known as the "law of constant heat summation". All it means is that no matter how many steps the chemical
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Maggie Mitchell IB Chemistry Prd. 5 THE HALOGENS LAB Date: 9/11/13 Purpose: The purpose of this experiment was to observe and record the halogens’ (NaF‚ NaCl‚ NaBr‚ and KI) reactions with the chemicals Ca(NO3)2‚ AgNO3‚ and NH4OH and use these observations to identify an unknown halogen. Data: (see next page) TABLE 1: REACTIONS OF HALOGENS WITH CA(NO3)2‚ AGNO3‚ AND NH4OH REACTION NAF NACL NABR KI REACTION W/ CA(NO3)2 solution turns cloudy and precipitate forms clear precipitate
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important step in any kind of organic chemistry lab and will help us be better at accomplishing the experiment in a much faster and accurate rate than from before. Experimental To begin the experiment‚ a tea solution must be made by incorporating a tea bag into a beaker filled with almost boiling water and the weight of the tea bag should be given from the instructor‚ just for result comparison purposes. Place 20 mL of water in a 50-mL beaker and proceed to heat until a near boiling state has been
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Determining the Specific Heat of an Unknown Metal Objective: To determine the specific heat of an unknown metal through the use of a calorimeter. Background: The specific heat of any substance represents the quantity of heat energy in joules required to heat one gram of the substances by one °C. The specific heat of a substance is dependent upon the temperature; this means that there is a temperature range for which the specific heat of a substance applies. For metals and metallic substances
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Specific Heat Lab Report “Here are the facts we confront; No one is against conservation. No one is against alternative fuel sources.” – J. D. Hayworth Research Question: Does the number of hydrocarbons that a fuel is composed of affect how much it will ignite? If so‚ consider the following: What is the quantity and concentration of the combustion that is released and how can that be measured in other (more coherent) means? These are the fuels that were seasoned throughout the
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ENGINEERING LAB 1 (MEC 2700) LABORATORY MANUAL JULY 2007 Table of Contents Experiment 1: Heat Capacity of Gases Experiment 2: Thermal and Electrical Conductivity of Metals Experiment 3: Heat Pump Experiment 4: Heat Conduction Experiment 5: Free and Forced Convection Experiment 6: Thermal Radiation Experiment 1: Heat Capacity of Gases 1. BACKGROUND The first law of thermodynamics
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Department of Chemistry Extraction and Sublimation Experiment #4 10/02/13 Introduction Caffeine is a stimulant found in tea‚ coffee‚ cocoa‚ OTC medication‚ and cola drinks.It stimulates the brain and the central nervous system‚ so that a person feels less tired and more alert. The purpose of this lab is to determine the amount of caffeine in tea. The major component of tea is cellulose which is a polymer of glucose. Materials Lab coat Goggles Graduated cylinder 1 tea
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In the lab testing the heat of a reaction to understand changes in enthalpy in an exothermic reaction‚ the group hypothesized that if the amount of reactant is changed then the amount of heat produced (exothermic) will increase. This hypothesis was supported through the data as each of the six trials produced heat and the larger the piece of magnesium the larger the change in heat was. In the first trial the group had .085 grams of Mg and after being placed in 3 ml of 21.8℃ HCl the temperature of
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Analysis of a Chemical Reaction Purpose: To observe a chemical reaction and to use qualitative and quantitative evidence to identify this reaction from among four possibilities. Hypothesis: I think the result is going to produce water. I think this is going to happen because there is hydrogen and oxygen inNaHCO3. Materials: -Test tube clamp - 150 mm test tubes (2) - burner - retort stand - clay triangle - iron ring - crucible Procedure: Part A: 1. Add 0.5 g of NaHCO3
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Honors Chemistry Period 2 September 22‚ 2013 PRE-LAB Title: Density of Metals – Shot Lab Purpose: The purpose of this lab is to find out the density of different metals using their mass and volume. If the volume and mass for the metals Nickel and Copper are found‚ then we can figure out the density. Materials: Metal shot Plastic rinse bin Electric Balances Calculator Graduated Cylinders Water Wire Gauze Weigh Boats Pre-lab Questions: 1) The volume of the water is 43.0 mL
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