Thermodynamics- Enthalpy of Reaction and Hess’s Law Objectives: 1. To calculate the heat of reaction of a given reaction using the concepts derived from Hess’s Law. Pre-lab Questions: 1. Define Heat of Reaction. The enthalpy change associated with the completion of a chemical reaction. 2. Define Specific Heat. The energy it takes to raise the temperature of 1 gram of a substance by one degree Celsius. 3. Calculate the heat of reaction assuming no heat is lost to the calorimeter. Use correct
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points are properties that can easily be determined and help in identifying a substance. These properties can be found in chemical literature ad reference tables‚ and can be used to distinguish a pure substance from many other pure substances. In this lab you will use the pure substance Paradichlorobenzene and determine its melting an freezing points by warming and cooling a sample of the substance‚ then plotting heating and cooling curves and analyzing them. Data that you collect will represent the
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this recrystallization lab in order to achieve the desired results‚ which included heating the solvent‚ completing a hot filtration‚ completing a vacuum filtration of a chilled solution‚ as well as drying and calculating the weight and melting point of the final version of the sample. I began the lab with 1.5 grams of the impure acetanilide solute and ended the lab with 0.05 grams of pure acetanilide crystals. The percentage of pure acetanilide I recovered during this lab was 3.33%‚ which is lower
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Formula of a Hydrate Lab Design: Problem: What is the chemical formula for a hydrated copper (II) sulphate compound? Controlled Variable: The mass of hydrated copper (II) sulphate. Responding Variable: The mass of dehydrated copper (II) sulphate‚ mass of H2O Materials: Ones on the handout + Hot plate. Procedure: 1. Mass 3.00g of hydrated copper (II) sulphate using electronic balance 2. Measure the mass of a thin‚ crucible dish using electronic balance 3. Gently pour hydrated
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Krupa Desai Cell Biology April 3‚ 2013 Lab: Biosynthesis of Starch Introduction: In this lab we learned the concept and procedure of synthesizing starch. We also learned the effects of pH and temperature on the reaction rates of amylase.. In the process of the synthesis lab we learned phosphorylation using a potato‚ which was what we synthesized. The phosphorylation took place after the addition of primer. There are two different types of starches used are amylose and amylopectin. To test
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Ashley Huston ILab‚ Week #2 CATIONS AND ANION LAB Introduction The purpose of this lab is to demonstrate a double-replacement reaction of ionic compounds. In this experiment‚ you will combine two ionic compounds. Both compounds are soluble in water. If a response happens between these two compounds‚ then a precipitate will form because one of the two resultant compounds is not soluble in water. This is a hint that a reaction took place. Cations are positively charged ions that are attracted
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Pre-Lab Work Sheet Which type of compound usually has higher melting points: ionic compounds or covalent compounds? What is the reason for this difference in melting points? (3 points) Ionic compounds have higher melting and boiling points than covalent compounds. The electrostatic attraction in an ionic bond is very strong hence a lot of heat energy is required to break it down‚ ionic bonds have high melting and boiling points. In covalent bonds‚ the intermolecular forces are very weak and
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AP Lab #5 Plant Pigments/Photosynthesis I. Identifying the Effects of Different Variables of Light and Carbon Dioxide on the Rate of Photosynthesis and Observing the Separation of Pigments Through Chromatography II. Introduction Plants have a variety of pigments‚ all of which absorb a different color of light. The three main pigments are chlorophyll a‚ chlorophyll b and carotenoids. Chlorophyll a is the primary plant pigment that absorbs red and blue light‚ which ultimately appears green to the human eye
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Flame Lab Objective: How an electron absorbs energy and re-emits it as light and why different elements have different spectra. Also to learn how to use flame tests to determine the identity of unknown mixtures. Hypothesis: We know that certain compounds will burn certain flame colors because they emit different wave lengths. Introduction: Neils Bohr made the “Bohr’s Model” in 1922‚ he found that electron travel in specified fields – which‚ when excited‚ will jump to different rings
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Lab Report: Stoichiometry Lab Oct. 27‚ 2011 Claire Elizabeth Lab Partners: Hannah Signature:___________________ Introduction- Baking soda and vinegar are two common materials found in almost every household. That‚ plus the fact that all the starting and finishing materials are non hazardous and safe‚ is why this is one of the first chemical reactions that many people are exposed to The purpose of this experiment tests which of the two reactants (vinegar and baking soda) is the limited
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