The Harcourt Essen Experiment The aim of this investigation is to: 1) find the rate equation for the reaction between hydrogen peroxide, potassium iodide and sulphuric acid by using the iodine stop clock method and plotting graphs of 1/time against concentration for each variable. Then to find the activation energy by carrying out the experiment at different temperatures using constant amounts of each reactant and then by plotting a graph of in 1/t against I/T, 3) to deduce as much information about the mechanism as possible from the rate equation. The first experiments investigate the order of reaction with respect to the reactants; hydrogen peroxide, potassium iodide and sulphuric acid by varying the concentrations and plotting them against 1/time. An initial rate technique is used in this experiment so ‘the rate of reaction is inversely proportional to time.’ To find the order of reaction in respect to the reactants, 1/time is plotted against the concentration of Hydrogen Peroxide using the equation: 1/t = k(a) ͯ t = time, a = volume of reactant, k is a constant of proportionality; x is the order of reaction. Because k is a constant of proportionality 1/t is directly proportional to the rate of reactant. Then to find out the order of reaction in a catalysed system the volume of ammonia molbydate is varied and the concentration of the other reactants kept the same. Thirdly to investigate the activation energies, the concentrations are kept the same and the temperature is varied. Background information: The Harcourt Essen experiment consists of two reactions: 2H+ (aq) + H202(aq) + 2I-(aq) 2H2O(l) + I2(aq) This is the first reaction in the Harcourt Essen experiment. The iodine is oxidised to produce I2 wh... ... middle of paper ... ... point was subjective; however it would have been a systematic error because I consistently judged the end point of my experiment. To eliminate this inaccuracy I should have used a colorimeter to judge the end point of my experiment. Also the stop clock had a degree of percentage error measured by: There was also a percentage error with the graduated pipettes calculated by: The percentage error of the burette: The percentage error of the graduated pipettes: Overall percentage error: There is also the potential of human error within this experiment for example finding the meniscus is important to get an accurate amount using the graduated pipettes and burettes. There is a possibility that at one point in the experiment a chemical was measured inaccurately affecting the results. To resolve this, the experiment should have been repeated three times.
Abstract: This week we experimentally determined the rate constant k for the reaction 2HCl (aq) +Na2S2O3 (aq) → S (s) + SO2 (aq) + H2O (l) + 2NaCl (aq). In order to do this the average reaction time was recorded in seconds during two trials. The data from the experiment shows this reaction is in the first order overall: rate=.47s-1 [HCl]0 [Na2S2O3]1. These findings seem to be consistent with the expected results
The Effect of Changing the Concentration of the Enzyme Catalyst on the Rate of Reaction on Hydrogen Peroxide
The objective of part A was to determine the rate of the substitution reaction between 1-Chlorobutane and KOH. This information was obtained by using the titration method to record the concentration of KOH over a given amount of time. To start this procedure, 1-Chlorobutane was added to a round bottom flask, which was connected to a reflux apparatus. Once it was observed that reflux had started the KOH was added with EtOH; this is the start of the reaction. The aliquot was then titrated with 0.100 M HCl and the concentration was noted at each interval. By graphing the data one can determine the order of the reaction and the rate of the leaving group. This data will provide the type of the reaction, whether it is SN1 or SN2.
Possible sources of error in this experiment include the inaccuracy of measurements, as correct measurements are vital for the experiment.
Investigation to find out if changes in concentration of acid affect the rate of a chemical reaction
In this experiment, there were several objectives. First, this lab was designed to determine the difference, if any, between the densities of Coke and Diet Coke. It was designed to evaluate the accuracy and precision of several lab equipment measurements. This lab was also designed to be an introduction to the LabQuest Data and the Logger Pro data analysis database. Random, systematic, and gross errors are errors made during experiments that can have significant effects to the results. Random errors do not really have a specific cause, but still causes a few of the measurements to either be a little high or a little low. Systematic errors occur when there are limitations or mistakes on lab equipment or lab procedures. These kinds of errors cause measurements to be either be always high or always low. The last kind of error is gross errors. Gross errors occur when machines or equipment fail completely. However, gross errors usually occur due to a personal mistake. For this experiment, the number of significant figures is very important and depends on the equipment being used. When using the volumetric pipette and burette, the measurements are rounded to the hundredth place while in a graduated cylinder, it is rounded to the tenth place.
Chemical kinetics is a branch of chemistry that involves reaction rates and the steps that follow in. It tells you how fast a reaction can happen and the steps it takes to make complete the reaction (2). An application of chemical kinetics in everyday life is the mechanics of popcorn. The rate it pops depends on how much water is in a kernel. The more water it has the quicker the steam heats up and causes a reaction- the popping of the kernel (3). Catalysts, temperature, and concentration can cause variations in kinetics (4).
In this lab, it was determined how the rate of an enzyme-catalyzed reaction is affected by physical factors such as enzyme concentration, temperature, and substrate concentration affect. The question of what factors influence enzyme activity can be answered by the results of peroxidase activity and its relation to temperature and whether or not hydroxylamine causes a reaction change with enzyme activity. An enzyme is a protein produced by a living organism that serves as a biological catalyst. A catalyst is a substance that speeds up the rate of a chemical reaction and does so by lowering the activation energy of a reaction. With that energy reactants are brought together so that products can be formed.
In this lab experiment, around 5 grams of hydrogen peroxide went through a chemical reaction with potassium iodide, producing oxygen gas and water vapor. After three trials of the experiment concluded, Dalton’s law of partial pressure and the ideal gas law was used to determine the number of moles of oxygen produced and the percent hydrogen peroxide in an aqueous solution. The average number of moles of oxygen produced within the experiment was 0.002537 mol. O2 and the average mass percent of hydrogen peroxide was calculated as 3.434%. The mass percent of hydrogen peroxide was slightly over the accepted amount of 3%, indicating that some tiny errors had occurred during the experiment.
The rate law for this iodine clock reaction is rate=k[I-][S2O82-]. The rate law could not have been predicted using the coefficients in the balanced chemical
The aim is to find out how does the rate of reaction between sodium thiosulphate
The purpose of the experiment is to study the rate of reaction through varying of concentrations of a catalyst or temperatures with a constant pH, and through the data obtained the rate law, constants, and activation energies can be experimentally determined. The rate law determines how the speed of a reaction occurs thus allowing the study of the overall mechanism formation in reactions. In the general form of the rate law it is A + B C or r=k[A]x[B]y. The rate of reaction can be affected by the concentration such as A and B in the previous equation, order of reactions, and the rate constant with each species in an overall chemical reaction. As a result, the rate law must be determined experimentally. In general, in a multi-step reac...
The point of this lab is to learn about systematic errors, which occurs when a mistake happens when setting up an experiment. When a systematic error occurs the accuracy of the experiment is thrown off. The point of the experiment was to figure out the relationship between precision and accuracy.
This report discusses the effect of the reactants’ concentration on the rate of the chemical reaction. Based on the results and evaluations, it is proven that the reaction rate increases as the concentration of hydrochloric acid increases. The collected data has shown that the 2 M hydrochloric acid has a faster reaction rate than the 0.5 M acid, due to its larger volume of water displacement. In conclusion, the results obtained from the experiment support the hypothesis stated.
One vital process in the human body observed in chemistry is the idea of chemical kinetics. Chemical kinetics is the study of the rate of reactions, or how fast reactions occur.1 Three factors that affect chemical kinetics are concentration, temperature, and catalysis. As the concentration of a substance increases, the rate of the reaction also increases.1 This relationship is valid because when more of a substance is added in a reaction, it increases the likelihood that the