REFERENCES GENERAL CHEMISTRY FOR ENGINEERING AND SCIENCE II CHE 152-50 Factors Which Influence the Rates of Reactions pages 1-10 OBJECTIVES To examine the factors which cause the rate of chemical reactions to change. QUESTION The question that was proposed for investigation was: Do all factors change the rate equally? Background Discussion For this experiment you have to have a basic understanding of Collision Theory to understand what’s going on in the experiment. Collision Theory is a model of chemical reactions in which a reaction occurs after a collision containing enough energy occurs between two reactant molecules. This model has five factors which can be affected and they are the nature of reactants, temperature, concentrations, surface area and catalyst. If one of these were changed then the reaction could occur faster or slower depending on what was changed. Sample Calculations Rate Law: 2A + B→C,is rate=k[A][B] (Lab Guide pg.6) PROCEDURE (Attached) DATA TABLES/CALCULATIONS (Attached) RESULTS HYPOTHESIS All factors change the rate of reaction equally. OBSERVATIONS In this experiment there five different phases and in each a different factor of the Collision Theory was tested. The first phase was called, Nature of the Reactants and it had three parts to it. In the first part of it which was steps 1-4, 5 pieces of mossy zinc were put into 3ml of 2M H_2 〖SO〗_4 and during this time bubbles were produced. After a few minutes the zinc was removed from the acid and it was now clean zinc. In the second part of phase 1 which was steps 5-8 4 different pieces of clean zinc were placed in 4 different acids. The acids were Hydrochloric ... ... middle of paper ... ...e will also become faster. In phase one, Nature of the Reactants five different metals were placed in the 2M HCl they all reacted differently with magnesium being the most reactive and copper being the least reactive. In phase two, Concentration, zinc was placed in different concentrations of 6M HCl. The higher the concentration was the more reactive the metal was. Next in phase three, Temperature, zinc was added to 6M HCl which was a different temperatures and the zinc was the most reactive with the HCl in the boiling water and least reactive with the HCl in the ice bath. Then in phase four, Surface Area, the powered zinc was more reactive then the piece of zinc in the 6M HCl because it had more surface area to be covered than the piece of zinc. Lastly in phase 5, Catalyst, the 3% H_2 O_2 was reactive with the 5 drops of 〖FeCl〗_3 but not with the 5 drops of water.
However, only experiments IV “Effect of Copper Metal” and V “Effect of Temperature” had reasonable results, so copper metal and temperature are the more effective factors. The less effective factors are the changes in concentrations of "H" ^"+" ions and "C" _"2" "O" _"4" "H" _"2" particles. This observation is represented in experiments II “Effect of "H" ^"+ " Ions” and III “Effect of "C" _"2" "O" _"4" "H" _"2" Concentration.” Both runs 2B and 2C had the fastest times of 25 seconds and 86 seconds
For this experiment we have to use physical methods to separate the reaction mixture from the liquid. The physical methods that were used are filtration and evaporation. Filtration is the separation of a solid from a liquid by passing the liquid through a porous material, such as filter paper. Evaporation is when you place the residue and the damp filter paper into a drying oven to draw moisture from it by heating it and leaving only the dry solid portion behind (Lab Guide pg. 33.).
Input variables In this experiment there are two main factors that can affect the rate of the reaction. These key factors can change the rate of the reaction by either increasing it or decreasing it. These were considered and controlled so that they did not disrupt the success of the experiment. Temperature-
For this experiment, you will add the measured amount of the first sample to the measured amount of the second sample into its respectively labeled test tube then observe if a reaction occurs. In your Data Table, record the samples added to each test tube, describe the reaction observed, if any, and whether or not a chemical reaction took place.
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...
It is important however to note that the NH4 and K ions are still in
I would then add a fair amount of Sodium Triphosphate. If the white precipitate and only the white precipitate remains, I could be sure the solution did in fact only contain Ca2+ Ions. Scenario 2: For scenario two, I would add some Potassium Ferrocyanide to the solution supposedly containing Zn2+ and Ca2+ ions. If the solution yielded a yellow precipitate, Zinc is present. If only a white precipitate remained, Ca2+ is present.
The purpose of the lab was to show the effect of temperature on the rate of
The aim of this experiment was to investigate the affect of the use of a catalyst and temperature on the rate of reaction while keeping all the other factors that affect the reaction rate constant.
The fourth factor is to add a catalyst, but in this experiment we did not add a catalyst. Knowing the collision theory, it makes my predictions clearer with what is going to happen when the experiment will take place.
The faster the cross disappears the faster the reaction and by timing how long this takes, we can establish the rate. of the reaction of the. I predict that the greater the concentration of sodium thiosulphate. solution in the experiment, the faster the chemical reaction will take. place. The sand is a sand.
We have no gases and solids involved, therefore it is easy to deal with solutions. Similarly, the use of a catalyst complicates things, and if used incorrectly could alter the outcome of the experiment. The theory behind this experiment is that increasing the concentration can increase the rate of the reaction by increasing the rate of molecular collisions. GRAPH I will place the reaction mixture on a paper with a black cross drawn on it. When the cross is completely obscured, the reaction will be finished.
Looking at the table of results above and the graph, it is shown that the higher the temperature got, the shorter the reaction time. The obtained results have been plotted on a line graph of the temperature of hydrochloric acid (y-axis) against reaction time (x-axis). This line graph in fig.2 also clearly shows that as the temperature increases, so does the speed of the reaction, shown by a reduction in the time taken. This corroborates the collision theory, where as the temperature of particles increase, the particles gain more kinetic energy and react with each other upon collision. This is shown as to happen in the hydrochloric acid, where the hydrochloric acid particles collide more with the particles of the magnesium ribbon as the temperature was increased. The above graph shows a gradual sloping curve, which gets steeper at higher temperatures. This shows that the reaction will reach a peak rate of activity as the gaps between the temperature and reaction times continue to decrease. The experiment fulfills the aim and clearly shows that as the temperature of a reaction is increased so does it’s rate of reaction, proving the hypothesis to be correct.
This experiment deals with motion. This study of motion is called Kinematics. Kinematics studies the possible motions. (http://www.britannica.com/EBchecked/topic/318099/kinematics). Kinematics is used to show the displacement of an object, the rate an object is moving (velocity), and the change in velocity (acceleration). This is graphed against time individually to determine if the motion is uniform or nonuniform and if the acceleration is uniform or nonuniform. Uniform motion is when an object has a constant speed and direction. Nonuniform motion is when there is either a change in speed or a change in direction. When the graphing has completed, other properties can be discovered like the instantaneous velocity. Instantaneous velocity is used to present the velocity of an object in a specific time when the velocity is changing. Vector and scalar quantities are also very important in this experiment.
In chemistry, catalyst is a substance which increases the rate of reaction with itself does not combine in reaction. The aim of this essay is researching more about catalyst, for instant how does catalyst work and the example of catalyst. Also, this research might useful for science international foundation students for support revision. First of all, this essay will describe Maxwell Boltzmann distribution diagram and give the meaning of collision theory, then it will discuss on Activation Energy. After that, activation complex will be explained using enthalpy diagram and catalyst pathway will be focused. Following this, there will be a describing about homogeneous and heterogeneous catalysts, also their own mechanisms and examples. Lastly, this essay will represent the catalytically poisoning.