In station B we tested the chemical reaction of decomposition; decomposition is the chemical reaction where the chemical compound is separated into elements or simpler compounds. In station C we tested the chemical reaction of double displacement; double displacement is the reaction where two compounds are replaced by two other compounds. In station D we tested the chemical reaction of single displacement; single displacement is when one compound is replaced by another compound. Each station is testing the law of conservation of mass by using each method in the lab. Purpose The purpose for this lab is to study the law of conservation of mass by using synthesis, decomposition, single replacement, and double replacement.
The aims are to examine the rate of evaporation and crystallization in a batch process, to achieve understanding of the basis principles of crystallisation and how these basic principles are modelled and to have a clear view of how to operate the machine. used for the experiment, the salts have been produce by batch evaporative crystallization is 0.12 kg. The concentration of the solution, the temperature to which the solution is heated or cooled, the nature of the solute like solubility, pressure around, time, the pureness of crystals, and others will be discussed as factors that affect the rate of crystallization. From the result, the salts have been produce by batch evaporative crystallization which is 0.12 kg whch is smaller than exact amount of salts that have been calculating in mass balance. DISCUSSION Crystallization either natural or artificial is the process of formation of solid crystals precipitating from a solution, melt or more rarely deposited directly from a gas.
Stoichiometry of a Precipitation Reaction October 1, 2013 Chem 131A-011 Partner: Purpose: This lab exercise combines the study of a precipitation reaction with stoichiometry. The amount of product produced in the precipitation reaction will be predicted to determine the theoretical yield. The reactants and products will be measured to determine the actual yield and the percent yield. Procedure: * 1.0 g of CaCl2·2H2O was put in a 100-mL beaker. * 25 mL of distilled water was stirred in to form the calcium chloride solution.
Lab Report Example Lab 16-1: How much calcium carbonate is in an eggshell? Elizabeth Shanor April 25, 2005 Purpose: Eggshells are composed in part of calcium carbonate. Calcium carbonate reacts with an acid to produce carbon dioxide, water, and a salt. The calcium carbonate in the sample eggshell will be determined by means of reaction with a carefully measured quantity of hydrochloric acid present in excess. The excess acid will be reacted with sodium hydroxide to determine how much acid remains.
The lesson of the lab is to teach us about Chemical kinetics, speeds and arrangements of molecules in a reaction during the process it goes from reactants to products. The reaction rates can be determined by two different kinds of equation. The average rate and the instantaneous rate. One is calculated by a change in time, and the other is calculated by a rate at a particular time a reaction has begun. Equations and mechanisms: Rate=k[A]^x [B]^y Rate=k[I]^x [S2O8]^y Rate1 k[A]1^x [B]1^y Rate2 k[A]2^x [B]2^y Rate3 k[A]3 [B]3 K=Ae -Ea/RT activation energy 2I-(aq)+S208^2-(aq)------> I2(aq)+2SO4^2-(aq) I2(aq)+ 2S2O3^2-(aq)------>2I-(aq)+S4O6^2-(aq) Apparatus and supplies: stopwatch, constant water bath, stirring rod, 10x75mm test tubes (5), 1ml pipet, 2ml pipet Chemicals: 0.200 M KI, 0.100 M K2S2O8, 0.0005 Na2S2O3, 2% starch solution.
In order to find the concentration of NaOH we need to tag along the following steps: a- note down the balanced chemical equation for the reaction C8H5O5K+NaOH→C8H4O4KNa+H2O b- pull out applicable information from the experiment: C8H5O5K V=0.025 dm3 C=0.2M NaOH V=0.021 dm3 C= ?? c- calculate number of moles
Percent H2O in Hydrate is equal 0.34/2.33=14.6% 3. The general formula of barium chloride hydrate is BaClg-nHZO, where n is the number of water molecules. Calculate the theoretical percent water for each value of n—divide the sum of the atomic masses due to the water molecules by the sum of all the atomic masses in the hydrate, and multiply the result by 100. Complete the table. | BaCl2 | BaCl2•H2O | BaCl2•2H2O | BaCl•3H2O | Sum of atomic masses (BaCl2) | 208.23 | 208.23 | 208.23 | 208.23 | Sum of atomic masses (nH2O) | 0 | 18.02 | 36.04 | 54.06 | Sum of atomic masses (hydrate) | 208.23 | 226.25 | 244.27 | 262.29 | Percent water in hydrate (theoretical) | 0% | 7.96% | 14.75% | 20.61% | In this lab we used a Balance, centigram
Assessed Practical: Planning Introduction: The aim of this experiment is to find the enthalpy change for the decomposition of sodium hydrogen carbonate. 2NaHCO = Na2CO3 + CO2 + H2O Using the enthalpy change of the following reactions. Sodium Hydrogen Carbonate: NaHCO3 + HCl = NaCl + CO2 + H2O Sodium carbonate: Na2CO3 + 2HCl = 2NaCl + CO2 + H2O Apparatus Sodium hydrogen carbonate Sodium carbonate Polystyrene Cup x 2 Measuring cylinder 50cm³ x 2 Weighing scale Weighing boats Thermometer degrees Spatula HCl acid 2M Prediction Background Information Hess' Law states that the enthalpy change for a reaction is the same whether the reaction occurs directly or in steps. This is a direct consequence of the fact that enthalpy, is a state function. One of the applications of Hess' Law is to determine the enthalpy change for a reaction by combining other reactions to get the desired reaction, then combining the enthalpy changes for the reactions to get delta H for the reaction under consideration.
Purpose of the Experiment: To produce diphenylmethanol from the reduction of benzophenone by using sodium borohydride as a reducing agent. To check purity of a product by using thin layer chromatography (TLC) and by performing a melting point. Introduction: The key step in the reduction of a carbonyl compound by either lithium aluminium hydride or sodium borohydride is the transfer of a hydride ion from the metal to the carbonyl carbon. In this transfer the hydride ion acts as nucleophile. The mechanism for the reduction of a ketone by sodium borohydride: (1) Method (Based on Chemistry Laboratory Manual): 1.
Chemguide – questions ELIMINATION MECHANISMS 1. In the presence of sodium hydroxide solution, 2-bromopropane can undergo either a substitution reaction or an elimination reaction. A mechanism for the substitution reaction is A mechanism for the elimination reaction is a) In the substitution reaction, the hydroxide ion is acting as a nucleophile, attracted by the slightly positive carbon atom attached to the bromine. How is the hydroxide ion acting in the elimination reaction? b) Use the mechanism to help you explain exactly what is happening during the elimination reaction.