Analysing Chemical Reactions in Combining Two Particles Essays

Analysing Chemical Reactions in Combining Two Particles Essays Analysing Chemical Reactions in Combining Two Particles Essay Analysing Chemical Reactions in Combining Two Particles Essay Introduction The procedure of fall ining two atoms ( reactants ) , in order to organize new product/products is called a reaction. The gait of a specific thing can be measured utilizing the rate i.e. , it describes how slow or fast a thing is. Rate is a measuring of the alteration that occurs in individual unit of clip, and its appropriate measurings are seconds, proceedingss, hours or even yearss. The gait with which the reactants react, is termed as the rate of the chemical reaction. Normally, for happening the rate of a reaction, either the sum of reactant used per unit of clip or the sum of merchandise produced per unit of clip should be calculated. During the procedure of reaction, the rate does non stay changeless and it varies throughout the procedure. It is higher in the initial phases and it gets reduced as the reactions advancements. In my position, the longer the procedure of reaction, the higher the reactions from the more reactants, Ieaving the fewer reactants with less opportunity o f responding My probe chiefly deals with a factor, which affects the rate of the reaction. The hit theory explains the rate of reaction. The cardinal thought behind this theory is that the hit among the atoms has to be difficult plenty for the reaction to take topographic point. The rate of reaction chiefly depends on how difficult the reacting atoms collide with each other. Collision theory When two chemicals react, their molecules have to clash with each other with sufficient energy for the reaction to take topographic point. This can be termed as the Collision Theory . The two molecules will respond merely if they have sufficient energy. Heating the mixture, will promote the energy degrees of the molecules involved in the reaction. Rising temperature denotes the faster motion of the molecules. This is termed as the Kinetic theory . Factors which affects the rate of reaction A accelerator changes the rate of a chemical reaction but it remains chemically unchanged throughout the procedure. It speeds up the chemical reactions. A accelerator plant by supplying the responding atoms a surface to lodge on, from where they can knock into each other. This increases the figure of successful hits. Merely really infinitesimal measures of the accelerator are required to bring forth a dramatic alteration in the rate of the reaction. This is true as the reaction returns in a different tract in the presence of a accelerator. An excess accelerator will perfectly do no difference. We could besides alter the size of the solid particle/surface country to increase hits by interrupting it into smaller pieces. This implies the atoms around it, in the solution will hold more country to work on so, there will be more utile hits. This produces a quicker reaction. If one of the reactants is a solid, the surface country of the solid will impact how fast the reaction goes. This is because the two types of molecule can merely knock into each other at the liquid solid interface, i.e. on the surface of the solid. So, the larger the surface country of the solid, the faster the reaction will be. Smaller atoms have a bigger surface country than larger atom for the same mass of solid. For case, masticating the nutrient increases the surface country and quickens the digestion. The concentration or force per unit area increases the figure of hits because if the solution is more concentrated, it implies there are more atoms of reactants strike harding between the H2O molecules, which make hits between the important atoms more likely. For gases, by increasing the force per unit area, you squeeze the molecules together and this will heighten the frequence of hits between them. This is besides described as the Collision Theory . Activation energy is the sum of energy required for the reactants to successfully respond. The reactants need a certain sum of energy, and any addition in excess energy, consequences in the successful hit. My Experiment I have chosen to look into, how the concentration of reactants affect the rate of reaction because it would be easier to mensurate and command the concentration variable. Temperature would hold been harder to command because it is difficult to mensurate it to a specific point and maintain it at that temperature because it s easy affected by the environment. Surface country would hold been harder to look into because the french friess were in varied sizes and forms. This made the measuring of the surface country hard, although if they were in a precise forms or sizes like regular hexahedrons, this would hold been possible. I found it difficult to believe of a suited accelerator to add in this reaction so, altering the rate of reaction by adding a accelerator would hold been hard for me. It was far easier to look into how concentration affects the rate of reaction. I will transport out this experiment by changing the concentration of hydrochloric acid added to a given sum of powdered m arble bit and mensurate the clip it takes to give off a certain sum of gas. The equation for this reaction is: CaCO3 ( s ) + 2HCl ( aq ) == gt ; CaCl2 ( aq ) + H2O ( cubic decimeter ) + CO2 ( g ) Apparatus Gas syringe Burette Conic flask Glass Delivery tubing Beaker Funnels Distilled H2O Top Pan Balance Stopwatch Hydrochloric Acid ( 1 Mole ) Land Marble french friess Thermometer Clamp Bung Prediction My hypothesis describes, the higher the concentration of hydrochloric acid, the faster the C dioxide will be given off. This is because as the concentration of the acid is increased, there are a greater figure of H+ ions ( produced by the acid ) in the same volume. Hence, there is a greater opportunity of the H+ ions clashing and hence responding with the atoms on the surface of the marble french friess. Here are some diagrams explicating this phenomenon: In the first diagram, there are a comparatively little figure of atoms and hence the opportunity that they collide will be reasonably low. They will clash less often. In the 2nd diagram, there are approximately twice every bit many atoms in the same volume. Therefore, the atoms will clash a batch more frequently. I besides predict that the gradient of the graph when I compare al the consequences will be a curve, get downing low, and so immersing really high at the terminal: Method Clamp gas syringe degree with a conelike flask and spile on a tabular array Weigh 6g of land marble french friess utilizing a top pan balance and topographic point it inside the conelike flask Use a burette to mensurate the volume of HCL and another to mensurate the volume of H2O. Decrease the measure by 10 % each clip ( 200ml of reactants ) Place both in a beaker, so pour it into the conelike flack catcher Ask a spouse to get down the halt ticker while you put the spile in topographic point Record how long it takes for the volume of gas to make 50ml Repeat experiment 3 times Calculate the norm it takes for the volume of gas to make 50ml Plot a graph to demo this To maintain my probe consistent and do certain there are no other factors, which could impact the rate of reaction, I will be utilizing the same equipments and same sum of grounded marble french friess in each experiment. I will utilize land marble french friess because it would give me a more accurate consequence than marble french friess. This is because, the surface country of the marble french friess would approximately be about the same where as larger pieces of marble french friess would hold different sum of surface country. This would impact the rate of reaction because there will be different sum of surface country for the reactants to work on. By doing the surface country approximately the same, the rate of reaction wo nt be affected by it. From my preliminary consequences, I conclude I would utilize 3g of marble french friess because after each reaction, there were some residuary marble french friess. If there was a deficit of marble french friess and the hydrochloric acid was nt used up, the volume of gas would nt be able to make 50ml so, in order to accomplish this, we need to mensurate the sum of marble french friess to be able to compare the consequences. We besides need to mensurate the sum of marble french friess to do the consequences more accurate. The measure of marble french friess would increase the rate of reaction because there would be more marble french friess to clash with the acid. To do the experiment less affected by other variables and do the consequences more precise, the measure on marble french friess demands to be consistent. I will utilize a top pan balance for mensurating the marble french friess because it measures to the nearest 0.01g. It will be more accurate than mensurating the marble french friess by the figure of spatulas I ve put in because the consequences would change. I will utilize a burette to mensurate the measure of hydrochloric acid and H2O because it would be more precise than utilizing a measurement cylinde r. This is because a burette measures to the nearest 0.1ml, where as a normal measurement cylinder merely measures to the nearest milliliter. This would do the consequences more accurate. I will utilize a gas syringe to mensurate the volume of gas because it is easier and more accurate than utilizing a H2O trough. This is because a H2O trough might allow some gases escape and it s difficult to command the volume of H2O inside the mensurating cylinder. This will do the consequences less accurate. Using a gas syringe will allow the gas flow more easy and will non allow any gases flight. I will clamp the gas syringe so it s non tilted and is flat with the conelike flask. This manner, the gas syringe will be less affected by gravitation and the gas will flux at a steady rate. If it was non in topographic point, gravitation would draw the terminal down so the timing it takes for the volume of gas to make 50ml would be altered and the consequences would non be right. I will take aid from person to assist me add the solution of acid and H2O into the conelike flask with the marble french friess, while I place the cork into the conelike flask. This is because I can get down the halt ticker when the reaction starts quicker. If I were to make this alone, by the clip I placed the solution and so get down the halt ticker, some of the reaction would hold already started so the clip it takes for the gas to make 50ml would be wrong. I will maintain the temperature the same each clip because it has a important consequence on the rate of reaction. To do certain temperature does non impact the probe, I will utilize a thermometer to mensurate the temperature of the acid and H2O because it will be the quickest. I have chosen the temperature of the acid and H2O to be 22 A ; deg ; because it was the temperature of the room at that clip and the temperature is less likely to alter this manner. If the solution it higher or lower than this temperature, we will put the beaker of H2O and acid into a larger container of hot or cold H2O to convey the temperature to 22 A ; deg ; . This will be easier than utilizing a Bunsen burner because that would alter the temperature excessively dramatically. From my preliminary consequences, I found mensurating the clip it takes for the gas to make 50ml would be best. This is because every reaction reached 50ml with the different per centum of concentration used. Using measurings below 50ml would be harder because the clip it takes to make it will be excessively speedy so, I will non be able to halt the stop watch exactly on clip. This would do the consequences more likely to be wrong. I will reiterate this experiment thrice in order to acquire accurate consequences. This is because we can compare our consequences with two others and do an norm. It will besides do it easier to descry any outliers. I have chosen to alter the concentration of acid by 20ml each clip because when I tried to alter by 10ml, the clip it took for the gas to make 50ml was excessively long. From preliminary consequences, I found that by doing the solution 100ml besides takes excessively long or the reaction to happen, so now I will do the solution 200ml. Now, the fury of consequences will be less and will be easier to compare. Safety I will be utilizing acerb, so at all times I must be really careful and MUST wear goggles. If any spills onto the tegument, it should be washed off instantly. Other Methods I could hold carried out this experiment in different ways. First I could respond the marble french friess with hydrochloric acid and utilizing a top pan balance, and step the weight of the reactants at the beginning of the reaction and step the weight at the terminal of the reaction for a certain period of clip and detect the measure of gas given off utilizing different concentration of acid. The method is acceptable for reactions bring forthing C dioxide or O, but non really accurate for reactions giving H ( excessively low a mass loss for truth ) . The reaction rate is expressed as the rate of loss in mass from the flask in e.g. g/min based on the initial gradient Second, I could hold used Sodium Thiosulphate and hydrochloric acid and see how the concentration of acid affected the clip taken for the reactants to bring forth a cloudy precipitate. The experiment involves watching a black grade disappear through the cloudy sulfur and clocking how long it takes to vanish. How the concentration of acid is measured The unit for concentration is moles per decimeter cubed or mol/dm? . One dm? is one liter so in other words it is how many moles per liter. A mole is 6.023 ten 1023 atoms and is called the Avogadro invariable. It is the figure of atoms which are found in a mass of 12 gms of carbons: How many moles of atoms would at that place be in 7 gms of N? The reply would be mass divided by the R.A.M. or 7 divided by 14 which is 0.5 moles. Table demoing how to thin hydrochloric acid to the desired concentration Concentration of acid ( M ) Amount of 2M acid ( milliliter ) Sum of H2O ( milliliter ) 0 0 200 0.1 10 190 0.2 20 180 0.3 30 170 0.4 40 160 0.5 50 150 0.6 60 140 0.7 70 130 0.8 80 120 0.9 90 110 1.0 100 100 Consequences By and large, the graph shows the higher the concentration of acid, the less clip it takes for gas to give off, which means, the faster it reacts. I drew a line of best tantrum which in fact proved to get down reasonably directly but so swerve upwards. The gradient of the lines starts increasing easy, so curves really steep. From 200ml-60ml of hydrochloric acid, the clip increases from 1.13s-10.63. The clip span additions by 9.5seconds. The mean rate of reaction increased here by -5.2ml/s. From 60ml-20ml of hydrochloric acid, the clip soared from 10.63s- 379.89. The clip increased by 369.26s. The clip increased by -123ml/s. Overall, the mean rate of reaction was rate of reaction decreased by 37.9ml/s. The ground why the line of best fit curves at the terminal is due to the fact that with the lower concentrations, as the HCl is used by responding with the marble french friess, the sum of H+ lessenings and hence it is less likely that the H+ ion collide with the marble french friess. T his explains why the line is so much flatter at the beginning compared to with higher concentrations. If a batch larger measures were used in the experiment, so we could hold got over this job and the curve would non demo up. The ground why the rate of reaction additions with the concentration is because when the concentration of the acid is increased, there are a greater figure of H+ ( aq ) ions in the same volume and hence there is a greater opportunity of the H+ ( aq ) colliding and hence responding with the atoms on the surface of the marble french friess. All the points on my graph are reasonably near to the line of best tantrum and there are no anomalousnesss, which in bend mean that my consequences are reasonably accurate. Evaluation: To measure, I am traveling to measure how good I carried out my probe and whether any betterments are necessary. My method was reasonably accurate. However, the fact that I used an linear thermometer to mensurate the temperature of the hydrochloric acid in my method besides means that I could hold made an mistake in mensurating the right temperature and it may hold been better to utilize a digital thermometer. Additionally, I could hold heated the H2O in a hot H2O bath to do certain that the H2O was at the right temperature. One major defect in the method I was utilizing included the remotion and application of the cork on to the conelike flask incorporating the reaction. When I started the reaction by adding the Ca carbonate french friess into the hydrochloric acid, I had to set the cork on consecutive off. However, this is non physically possible and it is inevitable that there will hold been some clip lost and even more significantly some gas would hold escaped before I would hold put the cork on. To work around this job, I could divide the marble french friess from the hydrochloric acid even in the conelike flask by infixing a division between the two reactants. This will let me the clip to set the cork on and so I can take the divider. One more job with my method is the clip when I am supposed to take a reading. When I said to my spouse when to halt, she might hold stopped after 50ml gas was given off. To do it more precise, informations logging equipment could hold been used, which would hold carried the same undertaking out automatically. However, I do believe that my experiment was conducted really good, as I had taken all the safety safeguards ( wore goggles, cleared the country etc. ) and checked all of my equipment prior to transporting it out. After each clip I had completed the method, I washed the needed equipment exhaustively to guarantee that no extra Ca carbonate was left over for the following clip I carried out the method. My consequences are besides dependable because I have got adequate points ( 10 ) to set on my graphs that I can pull a steadfast decision from ) . Yet, I still obtained some anomalous consequences. I found a few anomalousnesss in my consequences, which are circled on my graphs on the old pages. I believe these may hold occurred due to a little job with the gas syringe, where the syringe may hold been a spot stuck and therefore resulted in a slower reaction clip for when the gas is collected. Another ground for the anomalous points could include me taking wrong readings, where the syringe may hold been traveling excessively fast and to the bare oculus, the reading may look different to what it really is. I believe, to make a fairer and overall more dependable experiment, utilizing the experiment where you mark a black cross under a conelike flask and delay for precipitation to organize and do the cross disappear would be a more appropriate technique. Besides, I could mensurate the velocity of this reac tion by utilizing a light gate to observe the precipitate formation. The system consists of a light beam emitter and detector connected to computing machine and the reaction vas is placed between the emitter and detector. The light reading falls as the sulfur precipitate signifiers. This would be more accurate because it would diminish human mistake compared with the experiment I carried.