Germain Henri Hess (August 7‚ 1802–November 30‚ 1850) was a Swiss-born Russian chemist and doctor who formulated Hess’s Law‚ an early principle of thermochemistry. Born in Geneva‚ Switzerland‚ his father was an artist and in 1805 moved the family to Russia to find work. Beginning in 1822‚ Hess studied medicine at the University of Tartu. He qualified as a physician in 1825. Hess turned to chemistry after a meeting with Jöns Jakob Berzelius‚ the famous Swedish chemist‚ and went to Stockholm University
Premium Thermodynamics Entropy Russia
Determining the enthalpy of neutralization by calorimetry Anam Iqbal Partner’s name: Danielle Hodgson TA’s name: Karinna Section # 003 Due date: November 24‚ 2009 Introduction The purpose of the experiment is to determine the enthalpy of neutralization reactions by calorimetry. Calorimetry‚ is the science of measuring the amount of heat. All calorimetric techniques are therefore based on the measurement of heat that may be generated (exothermic process) or consumed (endothermic process). The
Premium Thermodynamics Enthalpy Sodium hydroxide
Enthalpy‚ represented by the sign ∆H in kJ/mol‚ is the heat change in a reaction. It shows whether how much heat is released or absorbed during the reaction. If the reaction is endothermic‚ the enthalpy would be positive and if the reaction is exothermic‚ the enthalpy would be negative. During a chemical reaction‚ which consists of breaking and creating bonds‚ heat is either absorbed or released. In this lab‚ the reaction uses the disassociation of an ionic compound ammonium nitrate shown in the
Premium Entropy Thermodynamics Temperature
Determining the Enthalpy Change for a Redox Reaction Criteria Assessed: Background Design Research Question What is the enthalpy change between the reaction of Zinc reducing Copper II ions? Purpose Determine the change in enthalpy for the redox reduction of zinc reducing Copper II ions. Independent Variable Dependent Variable The change in temperature Controlled Variables Materials/ Apparatus * Zinc powder * 2‚ Foam cups * 10 cm3 pipette * stopwatch * 1.00 M Copper
Premium Zinc Aluminium Iron
Calorimetry: Enthalpy of Neutralization Introduction: The purpose of this lab experiment was to determine the molar concentration of the unknown HCl by using a coffee cup calorimeter. A coffee cup calorimeter is made of Styrofoam cups with a thermometer that is placed from the top and into the calorimeter to measure the temperature as the reaction happens. The Styrofoam cup used for the calorimeter creates an isolated system as it acts as a heat insulator between the cup and the surrounding
Premium Thermodynamics Electrolyte Heat
Abstract This lab is performed in order to determine the total energy in a reaction between zinc and hydrochloric acid. The reaction is done twice‚ once to measure the heat of the reaction and again to determine the work done in the system. This is because Enthalpy equals heat plus work (∆H= ∆E+W). Heat and work can be broken down further into separate components so the equation used in lab is ∆H=mc∆T + PV. Many calculations are used in the lab to find out what cannot be measured directly (ex:
Premium Thermodynamics Energy Temperature
Calculating the Enthalpy Change of Reaction for the Displacement Reaction between Zinc and Aqueous Copper Sulphate Data Collection and Processing Observations: * Drops of water left on the inside of the measuring cylinder * Hole in the lid‚ possible escape route for gas or splash-back * The polystyrene cup felt warm during the reaction By extrapolating the graph we can estimate what the rise in temperature would have been if the reaction had taken place instantaneously. I can
Premium Thermodynamics Measurement Energy
high‚ we could have melted the product and lost it permanently. ------------------------------------------------- Reasons Melting Point: Professor has told us that our melting point is acceptable. The main reason is because during the Evap‚ the reaction occurred so fast that much of the solvent is contained in the crystals. So the actual melting point is nearly impossible to reach‚ and 10C-15C variation is acceptable. Questions 1). The infrared reading comparison between camphor and borneol+isoborenol
Premium Camphor Melting point Carbon dioxide
Determining the enthalpy change for the thermal decomposition of potassium hydrogen carbonate into potassium carbonate. Controlled Variables: 1. Volume of HCl ± 0.5 cm3 (± 2%) 2. Concentration of HCl‚ 3. Same mass of K2CO3 and KHCO3 within specified ranges of 2.5 – 3.0g and 3.25 – 3.75g respectively 4. Same calorimeter used i.e. polystyrene cup is used in this experiment 5. Same thermometer will be used ± 0.10K 6. Same source of K2CO3‚ KHCO3 and HCl Raw Data Results: The raw
Premium Thermodynamics Enthalpy Energy
Lab 3: Reaction Order and Rate Laws Name: Student Lab Partners: None Date of Experiment: 16 March 2014 Location: My House Course Number: CHE112 Abstract: When combining compounds‚ there are always two roles considered in the reaction. These are reactants and products. Reactants are the initial compounds before mixing. The products are synonymous with the term byproduct‚ or what remains when the reaction occurs. For example‚ Sodium (Na+) and Chlorine (Cl-)
Premium Rate equation Chemical reaction Reaction rate