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Rate of Reaction - Sodium Thiosulphate and Hydrochloric Acid
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?Aim??Investigation, to find out how the rate of reaction between Sodium?Thiosulphate and Hydrochloric acid is affected by changing the?concentration.??Introduction??I must produce a piece of coursework investigating the rate of?reaction, and the effect different changes have on them. The rate of?reaction is the rate of loss of a reactant or the rate of development?of a product during a chemical reaction. It is measured by dividing 1?by the time taken for the reaction to take place. There is five?factors which affect the rate of a reaction, according to the?collision theory of reacting particles: temperature, concentration of?solution, pressure in gases, surface area of...
due to?time restrictions.??· I used ICT to display my coursework, but I did not use it in anyway?that affected the experiment.??· I would like to do a further experiment to confirm my results.?However I am restricted by time and the available facilities which?means I cannot repeat it.??· Also instead of using a cross on a piece of paper I could use a?single beam of light until it could no longer be seen??· Use of computer to aid analysis of results??· Carry out all of the experiments on same day to improve accuracy??· Calculate more than ten tangents to improve accuracy?
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I will be investigating how... I will be investigating how the concentration of hydrochloric acid affects the rate of reaction between hydrochloric acid and magnesium ribbon. Equation: Mgs+2HClaq→MgCl2aq+H2g Planning: The input variables are: "¢ temperature of acid "¢ concentration of acid "¢ surface area of magnesium "¢ use of catalyst I will measure the concentration of acid and control the temperature of acid, surface area of magnesium, mass of magnesium and use of catalyst. The temperature of the acid will effect the rate of reaction because as the acid particles heat up, they gain kinetic energy, therefore move faster and collide more often and more successfully because the collisions are more energetic, therefore there are more collisions in a given time, and the rate of reaction increases. The surface area of the magnesium will effect the rate of reaction because the larger the surface area, the more collisions can take place in a given time, and the rate of reaction increases. The use of a catalyst will effect the rate of reaction because they give an alternative pathway that has a lower activation energy, therefore more of the collisions will result will result in reaction because they need less energy to be successful. This is the apparatus I will use: I will place some magnesium in a flask with an amount of acid. I will place a bung on the tube to prevent any gas from escaping. A tube will run from the flask to a graduating tube in a trough, both filled with water. I will then measure the amount of gas given off in a certain time. I will repeat the experiment 3 times in order to highlight any anomalies. In order to work safely, I will wear goggles in order to protect my eyes from acid. Prediction: I predict that the higher the concentration of the acid, the faster the rate of reaction. This is because there will be more acid particles in a given volume, therefore there are more collisions in a given time, and the rate of reaction increases. If the concentration was to double, I would expect the rate to double. This is in reference to a previous experiment with a reaction between marble chips and various concentrations of acid. It was proved in this experiment that doubling the concentration of the acid doubled the rate of the reaction, therefore the two sets of results were directly proportional. Pre-test: The concentrations we decided to use as our upper and lower values were 2M and 0.2M. From our pre-test, we discovered that 0.2M took too long to react, so the concentrations that we chose were not workable. We then decided to change our lowest concentration to 0.6M. Concentration of Acid M Time to react seconds 2 8.81 0.6 65.90 From the results of my pre-test, I will use 3cm of magnesium and measure the time to collect 10cm3 gas, as these provided workable results. Obtaining Evidence: Concentration of Acid M 1 2 3 2.0 8.52 7.84 8.42 1.8 11.52 6.49 9.12 1.6 9.35 16.02 10.01 1.4 13.95 11.58 11.21 1.2 13.25 13.78 16.05 1.0 18.81 18.24 20.72 0.8 32.78 32.81 22.02 0.6 67.51 48.28 62.46 Concentration of Acid M Temp Before ˚C Temp after ˚C Temp Before ˚C Temp after ˚C Temp Before ˚C Temp after ˚C 2 23 29 20 20 23 30 1.8 23 29 22 22 23 30 1.6 23 29 22 22 24 28 1.4 23 30 21 21 23 27 1.2 23 31 23 23 24 27 1 23 27 23 23 24 27 0.8 23 25 23 23 24 26 0.6 21 23 22 22 23 25 Concentration of Acid M Average Time seconds Rate x100 2 8.260 12.107 1.8 10.185 9.818 1.6 10.010 9.990 1.4 12.246 8.166 1.2 14.915 6.705 1.0 19.256 5.193 0.8 29.203 3.424 0.6 64.985 1.539 Results in bold are anomalies. Analysing and Conclusions From the temperatures taken before and after the reaction, I have discovered that the reaction is exothermic. My graphs show that the higher the concentration of acid, the faster the rate of reaction. This is because there are more acid particles in a given volume, therefore more collisions in a given time, therefore increasing the rate of reaction. If the concentration was doubled, there would be double the amount of acid particles in a given volume, double the amount of successful collisions in a given time, therefore the rate of reaction should double. This means that the concentration of acid and rate of reaction are directly proportional, as stated in my prediction. However, form looking at my results table, I have discovered that the rate of reaction is the concentration of the acid squared. This disagrees with my original prediction. Evaluating: The readings on my graph do not fit the best-fit line very well, as there are several anomalies, therefore the results are not very reliable. The anomalies could be due to the fact that we had to use two different bottles of acid during the experiment, so the concentrations could have been slightly different. We did parts of our experiment at different times, so the temperature in the lab could have been higher, therefore increasing the temperature of the acid, so the particles would have more energy, move faster, increasing the number of collisions, therefore altering the rate of reaction. Where the magnesium had oxidised, a substance had formed on the surface on the magnesium, which meant that the acid had to get through it to reach the magnesium, increasing the time to react. We did however try to make our data more accurate by using a syringe to measure small amounts of acid and water, and using as many decimal places as we could in our calculations. The temperature of the acid was hard to control, as it was controlled by the temperature of the room. If I was to repeat the experiment, I would use more varied concentrations in order to show more clearly the pattern, and also to attempt to clear any anomalies. I would also like to investigate larger concentrations of acid, but would have been hard to measure.   

I will be investigating how the concentration of hydrochloric acid affects the rate of reaction between hydrochloric acid and magnesium ribbon. Equation: Mgs+2HClaq→MgCl2aq+H2g Planning: The input variables are: • temperature of acid • concentration of acid • surface area of magnesium ...

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Introduction In this... Introduction In this assignment I will investigate hazard and prevention. This is three tasks assignment. In task one I will make a checklist and definition of checklist and why we should make a checklist for any place. For task two I have given an A4 sheet with tropical image of accidents. For this task I need to find out these accidents and write how I could prevent them. Fro task three I need to write all about hazards and anything related to this. Task one In this task I am going to make a checklist for my chemistry lab. Checklist is a tool to ensure all-important steps or actions in an operation have been taken. Checklist contains items important or relevant to an issue or situation. Checklist is a safety list. Checklist is a list of different equipment in a lab or home or office. Make sure that all the equipment listed in the checklist and it should check once or twice a year. A checklist helps us to find out what type of equipment we get a specific place, such as lab or home. If I don¡¦t have a checklist, than I can¡¦t tell what I have gets in a place such as lab or home. Checklist often confused with check sheet. Check sheet is a simple data-recording device. The check sheet is custom designed by the user, which allow him or her to readily interpret the result. I am going to make a checklist about G4 Chemistry laboratory. I will check each item once a year. Category Date of checking Any thing wrong Yes No Action Job Done First Aid Eye wash 20 /08/2002 Water line block Call an plumber Clear the line. Fire fighting Equipment Fire Extinguisher Fire Blanket Fire Alarm Fire Exit Sand Bucket Main Equipment Gas guard Electric power supply Gas tapes Electric sockets Equipment Broken bucket Bin bag Water bath Oven Special equipment Distilled water Eye/body protection Lab coat Goggle Spectacles Face shield Experiment safety Hazards warning sign Safety screen Task two a I have given an A4 sheet paper where they gave me a typical image of an accident waiting to happen in the laboratory. My task is to identify these accidents and explain how I could prevent them happening. List of the accident may happen in this laboratory: 1. A boy doing an experiment where chemicals will fall of on his body. And he didn¡¦t wear an eye protection. And height of the object is not appropriate for him. 2. A girl doing en experiment but her long hears were untied, under her hair there is a Bunsen burner with fire. 3. Middle of the class room there is water on the floor. 4. A boy opens an electric socket without teacher permission. He might get electric shock. 5. All students do not wear eye protection. 6. A girl playing with the rubber band and disturbing other to do their experiment. 7. A girl doing experiment but her test tube face at her chemicals will go on to her body. 8. A girl doing an experiment but her test tube faced straight to up. Hot chemicals may explore and fall on to her body. 9. A girl holding a hot bicker without a glove. 10. A girl looking to other girl and mistakenly she put her hand up on the hot gorse. 11. A boy carrying box but he can¡¦t see anything what happen to front. 12. Main exit door blocked by boxes. If fire in the room no one can get out. 13. Teacher given demonstration about chemical where students were too close and there is no safety screen. None of these students wearing goggle. 14. A girl put an iron stand at the edge of the tale. It could fall onto someone¡¦s foot. 15. Some one put a biker up on the gorse at the edge of the table. 16. Bunsen burner left with blue fire. I could prevent these accidents by: 1. Height of the object must be appropriate for him. And he must wear a goggle to do chemical experiment. 2. This girl must tie her hear up and when she does not use Bunsen burner she must left it with yellow coloured fire. 3. Clean the water as soon as possible. Otherwise someone may slip n the floor. And it may break their leg or hip. 4. Teacher must warn students about electric socket that students never try to open an electric socket. It is dangerous to get an electric shock. 5. All students doing various experiments, but none of them use eye protection. Chemicals or other thing could spill in to the eye. To prevent this happen teacher must tell students advantage of wearing a goggle which can save my eyes to have any damages. 6. Tell her play outside. 7. Test tube must not face to you or other people, because chemical may explore and go onto your body. 8. Test tube must put diagonally, because if test tube put straight up and chemicals heated than chemical will explore and could fall onto your body. 9. If anyone needs to hold some thing hot they must use glove. Because otherwise they might burn themselves. 10. If anyone does any experiment they must concentrate with their experiment. 11. Tell him to remove these boxes after the class. 12. Clear the door way. 13. Use a safety screen and student must wear goggle. 14. Put the iron stand middle of the table. 15. Put bicker and gorse middle on the table. 16. Bunsen burner must be left with yellow flame. Task two b In this task I will write about three accident and necessary emergency procedures could be used in these accident. There are the accidents: ƒ¾ Chemical in the eye ƒ¾ Chemical burn ƒ¾ Electric shock Chemical in the eye: splashes of chemicals in the eye can cause serious injury if not treated quickly. Recognition of chemicals there may be: "žÃ Intense pain in the eye "žÃ Inability to open the injured eye "žÃ Redness and swelling around the eye "žÃ Copious watering of the eye "žÃ Evidence of chemical substance or containers in the immediate area. Treatment: First thing do not allow the casualty to touch the injured eye or forcibly remove contact lens. Hold the affected eye under gently running cold water for at least ten minutes. Make sure that you irrigate both sides of the eyelid thoroughly. If the eye is shut in a spasm of pain, gently but firmly pull the eyelid open. Be careful that contaminate/rotten water does not splash the uninjured eye. Ask the casualty to hold sterile eye pad or any clean pad or non-fluffy materials over the injured eye. Than take or send the casualty to the hospital. Chemical burn: certain chemicals may irritate, harm or be absorbed through the skin, causing widespread and some times fatal damage. Recognition of chemical there may be: "žÃ Evidence of chemical in the vicinity "žÃ Intense, stinging pain "žÃ Later, discolouration and swelling of the affected area. Treatment: Never attempt to neutralise acid or alkali burn unless trained to do so. Do not delay starting treatment by searching for an ambulance. First make sure that injured area is safe. Ventilate the area and remove the casualty if necessary. And seal the chemical container if possible. Flood the affected area with water to disperse the chemical and stop the burning. Do this at least 20 minutes. Gently remove the pollute clothing during flooding the injury. Take or sand the casualty to hospital. Give the details about chemical to medical person. Electric shock: Domestic current, as used in home, office, college lab etc, can caused serious injury and even death. Action: do not touch the casualty if they contact with electrical current, he will be ¡§live¡¨ and risk electrocution. Do no use anything metallic to push away the electrical source. Try to switch off the socket or main power, if you can¡¦t switch off than stand on dry insulating materials such as a wooden box or telephone guide. Push the casualty¡¦s limbs away from the source with a broom, wooden chair or stool or push the push the source from the casualty, whichever is easier. If the casualty is unconscious, open the airway check for breathing and be ready to place them in recovery position. Cool if there any burn with cold water. Dial 999 for an ambulance. If the casualty seems to be unharmed, advise them to rest. Observe them closely and, if in doubt, call a doctor. If the hart stops apply the ABC Airway, Breathing and Circulation signs of life of resuscitation until a normal heartbeat returns or specific medical treatment is given. Task three Hazard & Risk The term "risk" is often confused with "hazard". A high voltage power supply, a sample of radioactive metal, or a toxic chemical may present a hazard, meaning that they present the potential for harm. Concentrated acids, for example, clearly present the hazard to the user of serious burns if they are handled incorrectly. A hazard is something with the potential to cause harm of life e.g. this can be a substance, part of a machine, form of energy, method of work or a situation. Harm includes death, injury, physical or mental ill health, damage to property, loss of production, damage to the environment or any combination of these. Risk is a measure of the likelihood that the harm from a particular hazard will occur, taking into account the possible severity of the harm. The risk is the probability or chance that the hazard posed by the chemical will lead to injury. Thus, concentrated sulphuric acid is a hazardous chemical; because it is very corrosive and reactive. However, provided it is handled in an appropriate way the risks it poses may be small. For the risk to be real: "žÃ The threat must exist. "žÃ There is likely to be magnitude of effect. "žÃ There is potential for occurrence. It is thus evident that hazards are something we can do little about. The hazard posed by a carcinogen, a concentrated acid or an explosive substance is inherent properties of the material. The risks they pose, however, can be and should be! minimised by initially preparing a suitable risk assessment. Risk Assessment is the process of analysing the level of risk, considering those in danger, and evaluating whether hazards are adequately controlled, taking into account any measures already in place and any work practices that may be in force. I have to fill a risk assessment for my Physics experiment. Sample of that risk assessment form as below: Components of Hazards There are number of components to consider in defining hazard: ľ Intrinsic properties of the hazard. ľ The nature of the equipment or from of the material such as vapour, mist, liquid etc. ľ The exposure-effect relationship. ľ The pathways and frequency of use ľ Aspects of worker behaviour the affect exposure to the hazard. ľ Mechanisms of action. Type of Hazards: There are different types of hazards: Chemical hazard: through a variety of action, chemicals can cause damage to health and property. Some of these actions are explosive, flammable, corrosive, oxidation, poisoning, toxicity, and carcinogenicity. Biological Hazard: mainly from infection or allergic reaction. Biological hazards include viruses, bacteria, fungi and other organism. Some biological hazards such as AIDS or hepatitis B are potentially life threatening. Physical hazards: these include noise, radiation such as ionising, electromagnetic or non-ionising, heat, cold, vibration and pressure. Ergonomic hazards, psychological hazards, Lateral water hazards, EM hazards, health hazards etc. Components of Risk; ľ Individual variation in susceptibility. ľ The numbers exposed. ľ The degree of individual risk. ľ The possibility of elimination of a less hazardous substance or process. ľ The possibility of achieving of the hazard. ľ Public opinion and pressure groups. ľ Social responsibility. Perception of Risk: People judge risks differently. Judgments are made on the ease of recall and imagining. For example, the role of the media in bringing risk issues such as AIDS or asbestos to public attention in one exercise of this judgment. While risk analyses will provide some estimate of a risk in numerical terms, presentation of quantitative facts on risk rates often does not work well. Statistical expressions of risk are only one dimension of risk, and these may be irrelevant to lay people who view risk qualitatively. Warning signs represent a hazard level between Caution and Danger. A warning indicates a potentially hazardous situation, which, if not avoided, could result in death or serious injury. All the chemicals in the laboratory must have warning sign and labelled, because without a warning sign or label no one will know is it a corrosive, flammable or other dangerous chemical. To be safe in a laboratory than all chemical must be label and must have a warning sign. Example of some warning sign: A survey carried out in school science laboratory publisher in education in science. The result of that survey most common accident in the laboratory as below: Accident Percentage Chemicals in the eye 23% Chemicals on the body 21% Cuts 20% Burn & scalds 15% Dropping, falling, slipping, lifting, knocking 7% Chemicals in mouth 4% Inhalation 4% Animal bites 3% Explosions 2% Electric shock 1% Most common accidents in laboratory show in the pie chart as below; The result of the survey tell that chemical in the, is the most common, because students does not follow the safety rule. In the safety rule they give everything what student should do when they enter in a laboratory. Before get this result I thought cut will be the height common accident, but in this result show chemical in the eye is the most common accident. This because students don¡¦t understand the important of wear eye protection. They didn¡¦t listen to their teacher. The safest place from accident is science laboratory, because they have rule which you must need to follow. And mostly accident happened in home, because we don¡¦t have any rule in home. That way in the home there are most accident happened. For safe in laboratory they made a safety rule. A sample of a safety rule in science laboratory is below: To be safe in the laboratory we must follow the safety rules and we must have hazards warning sign and label. And minimise the risk we should do risk assessment. Before using a lab first thing to do is make a checklist of the entire item in the lab. Than check these once or twice a year. Safety check is very important because if something wrong in the lab than from safety check we could know about it. Safety check helps us to find out any fault or any thing change we need to do. In your home you also need a checklist, because if any thing stolen from your home police will ask you what the things stolen. In this time you need a checklist. You also need checklist for checking is your all machinery or other things work properly such as your washing machine, freezer etc. so a checklist very important for any particular place.   

Introduction In this assignment I will investigate hazard and prevention. This is three tasks assignment. In task one I will make a checklist and definition of checklist and why we should make a checklist for any place. For task two I have given an A4 sheet with...

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