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GCSE: Patterns of Behaviour

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  1. The Effect of Catalase in the Breakdown of Hydrogen Peroxide

    The tertiary structures of enzymes allow their shapes to be unique, and though it is quite a complex structure, it assists the enzymes in "capturing" only specific substrates that fit the specifically made active sites. Therefore, the more enzymes that are added; the quicker the rate of the reaction. As the enzymes do not get used up, they are known as catalysts. Reactions occur exceptionally slow when a reaction lacks a catalyst. Similarly, by comparing the structure of an antibody and its function, one can see that both the antibody and the enzyme share the Lock and Key Principle, in which only specific substrates can fit in particular active sites.

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  2. Rates of Reaction

    Decimal value, and determine the overall order of reaction for the equation. For example, if the order of reaction for A was equal to zero, it means that the concentration of A has no bearing on the rate of reaction (because A0 = 1, which means A is cancelled in the equation). However, if [A] was equal to 1, the graph would be represented by a straight line. If the order of reaction was 2, the graph would form a curve directly related to an exponential function, as seen in algebra. The overall order of reaction is found by adding up the orders of reaction for the reactants (in this case just

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  3. The aim of this coursework is to investigate the rate of reaction between sodium thiosulphate solutions and dilute hydrochloric acid.

    is measure with a balance. * The volume of a gas is usually measured with a gas syringe, or sometimes with an upside down measuring cylinder or burette. * You could possibly record the mass or total volume at regular intervals and to plot graph. The readings go on the vertical axis and the time goes on the horizontal axis. Collision Theory A chemical reaction can only occur between particles when they collide. These particles may be atoms, ions or even molecules. There is a minimum amount of energy which colliding particles need in order to react with each other.

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  4. An Investigation to determine the factors which affect the rates of reaction between Marble Chips (CaCO3) and Hydrochloric Acid (HCl)

    And hence give more accurate results. The gas syringes only measured up to 100 cm3 and this meant that the gas syringe had to be reset, and this meant that some of the gas escaped whilst the equipment was being reset and hence the probability of recording accurate results was reduced. So all in all the scale method is the best method of collecting the gas being produced by the reaction. Possible variables: Independent Variable This changes and all other measurements vary with it Dependant Variable This is the dependant variable which means that this figure relies n the independent variable.

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  5. Some fuels are mixed with oxidising agents to produce explosives. An explosive such as gunpowder is designed to carry their own oxygen supply taking gunpowder as the example the potassium nitrate in the gunpowder acts as an oxidiser

    The greater the tension contained in this bonds, the more powerful the detonation will be, once they are broken apart. Some explosive mixtures oxidise faster than other because more oxygen is available.{4,3} Describe how UK methods of manufacture of propanone have changed since the beginning of the First World War. During the First World War propanone was manufactured by the dry distillation of wood in a process that excluded air. This method was not effective and not enough propanone could be made.

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  6. Oxidation reactions can be used to cause explosions due to the fact that these reactions can produce large volumes of products from a relatively small volume of reactants. The products mainly consist of hot gasses

    The oxidiser contains the oxygen needed for the reaction, instead of taking oxygen from the air, which means the reaction would be slower; this means the reaction can take place within a fraction of a second. During the First World War British shells had to be rationed, this is because of a lack propanone used in making cordite, the main propellant in artillery shells. Before the war the British had to import propanone, as they had no means of producing their own.

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  7. Investigate how varying the concentration of Sodium thiosulphate solution affects the rate of reaction with Hydrochloric Acid.

    A more concentrated substance has more molecules for a given volume than a more dilute substance. Because there are more molecules about, the frequency of successful collisions is greater, and the reactions happen faster. Prediction I predict that when I add more water to the sodium thiosulphate solution, the time it takes for the cross to disappear will lengthen. I predict this because, for particles to react they must collide with each other. If there is a higher concentration of sodium thiosulphate particles in a given volume there, is a higher chance of the particles colliding together and reacting.

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  8. An Experiment to Investigate the Effect of Changing the Concentration of Hydrochloric Acid on the Rate of the Reaction between Hydrochloric Acid and Sodium Thiosulphate

    Molarity is the number of moles of solute dissolved in one litre. of solution. The units, therefore are moles per litre, specifically it's moles of solute per litre of solution. Rather than writing out moles per litre, these units are abbreviated as M or M. We use a capital M with a line under it or a capital M written in italics. So when you see M or M it stands for molarity, and it means moles per litre (not just moles). You must be very careful to distinguish between moles and molarity.

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  9. Investigating the rate Of reaction between Acid and marble

    I have to control this by using the same one each time or it will affect the results of the experiment. Preliminary work Acid As part of my planning I had to do some preliminary tests so that I could find out what the best conditions are to get the best results out of my experiment. I did an experiment to find out what the best acid to use for my experiment was. The acids that I used for my preliminary work are as follows: Sulphuric acid - H2SO4 Nitric acid - HNO3 Carbonic acid - HCO3 The tables below show the results which I obtained from my preliminary experiments.

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  10. How Does Acid Concentration Affect the Rate of Reaction of Magnesium with Dilute Hydrochloric Acid?

    The rate at which this takes place is referred to as the rate of reaction. The rate of reaction is defined as the rate of loss of reactants (or rate of formation of products) during a chemical change. Rate is a measure of the change that happens in a single unit of time. There are a number of ways to alter the rate of reaction. In some cases, it is important that a reaction must be slowed down. In most cases, it is important that a reaction takes place much faster. When altering the rate of reaction, one has to understand the Particle Collision theory.

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  11. Investigate the affect of temperature of sodium thiosulfate and hydrochloric acid against rates of reaction.

    Therefore, from my results I can say that, the higher the temperature, the faster the collision rate. There was a systematic error on the 46�c and 49�c temperatures, as they are both the same. From my results, the 49�c temperature should have affected the rate of reaction quicker, because the temperature is higher. I also found an error when I did my 39�c test. The result is 5 seconds slower than the 38�c test. The result should have been 5 seconds quicker with the 39�c test.

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  12. How the surface area/particle size affects the rate of reaction by measuring the amount of gas produced and weight loss in a reaction between small, medium and large pieces of Marble Chips (Calcium Carbonate) and Hydrochloric

    Apparatus that will be used: * Conical flask * Cotton wool * Scales * Measuring cylinder (50ml) * Stopwatch Method * Take one large piece of Calcium Carbonate and record its weight. * Measure 100cm� of hydrochloric acid (using measuring cylinder). * Place the flask on the scales. * Add the marble chip and hydrochloric acid to the conical flask at the same time. * Start the stopwatch. * Record the weight loss (gas given off) every 30 seconds for the 3 minutes of the reaction, then every 1 minute for 2 minute, then every 2 minutes until the reaction stops.

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  13. The aim of this experiment is to determine the rate of reaction of hydrolysis on halogenalkanes. Explanation In this experiment, you compare the rate of hydrolysis of chlorine, bromine and iodine

    This is due to the decrease in bond enthalpy as the halogen atom radius increases the bond gets longer and weaker and chlorine is the most electronegative and iodine the least electronegative. Electronegativity is the ability of an atom to inductively pull electrons towards it. The more electronegative an atom, the tighter it pulls the electrons, the higher the electronegativity, the more strongly an atom attracts, and Note electronegativity is the characteristic of an atom to take up electrons from another atom in an attempt to fill its outer shell.

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  14. The object of this investigation is to determine the enthalpy change for the reaction CaCO3 (s) → CaO (s) + CO2 (g) by an indirect method based on Hess' Law. Hess's law states that the enthalpy change for any chemical reaction

    whole number as it is unrealistic to measure to a point of a ?C with this type of thermometer and the masses rounded up to 2 decimal places for greater accuracy. Calculations It's possible to use the formula E = mc ?T, where E = energy transferred, m = mass of HCl, c= specific heat capacity of HCl and ?T = temperature change. This formula can be used for calculating the energy transferred in the following reactions ? ?H1, CaCO3 (s)

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    A common misconception is that an increase in concentration increases the speed of the particles moving around in it or the amount of energy they have, this is not the case as the increase in concentration merely increases the surface area which facilitates the reaction; this can be further helped if the particles being used are of a small size. See diagram below which compares small particle size with the larger particle size. The hypothesis of this experiment is that an increase in the concentrations of Magnesium and Hydrochloric acid will increase the rate of reaction which is measured by the amount of hydrogen produced.

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  16. GCSE Chemistry investigation: the reaction of sodium thiosulphate with hydrochloric acid

    2HCl(aq) + Na2S2O3(aq) 2NaCl(aq) + SO2(g) + S(s) + H2O(l) Equipment used: Hydrochloric acid Sodium thiosulphate 10cm3 cylinder 100cm3 cylinder 250ml conical flask Stopwatch Thermometer Piece of paper with cross on Goggles Method 1. Mark a cross, (with a fine pen), on a piece of paper. Place on the table. 2. Place a 250ml conical flask on to the cross, (see the cross through the glass). 3. Measure out 50cm3 of sodium thiosulphate in to a 100cm3 cylinder, and pour into the flask. 4. Measure out 5cm3 of hydrochloric acid in a 10cm3 cylinder.

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  17. How does changing the concentration of hydrochloric acid affect its rate of reaction with magnesium?

    The reaction has a lower temperature, which means that there is lower activation energy. There are an increased number of successful collisions, therefore an increase in the rate of reaction. In this experiment, I am going to investigate the effect of concentration on the rate of reaction between two chemical reactants. Preliminary experiment Before doing the actual experiment, I did a preliminary study to help me find a suitable range for the concentrations and how to control the temperature for the main experiment.

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  18. Rate of reaction

    So this means if the concentration of any reaction in a solution is increased, the rate of reaction is increased too. 3 Surface area- If a solid or a solid catalyst is broken down into smaller pieces the rate of reaction increases. Therefore, there is more chance that a reactant particle will hit the solid surface and react. The increase in speed happens due to the smaller pieces of the same mass of solid have a greater surface area when compared to larger piece of a solid.

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  19. Potato sample that was cut to size was placed into test tube and clamped to retort stand. 4. 10ml of hydrogen peroxide was poured carefully into test tube with potato sample

    Control experiment was conducted for comparison of results. Results Size Surface Area (cm ) Volume (cm) Amount of oxygen produced (test1) in ml Amount of oxygen produced (test 2) in ml Control 0 0 0 0 1 cm (whole) 1x1x1=6 1x1x1=6 6 7 1/2 cm (halved) (1x 1/2)x4=6 1x1x2=2 2+6=8 1cm 8 9 1/4 cm (quarters) (1/2x1/2) x2= 1 2.5x4=1 =10 1cm 10 11 Size of cube Group1 (test1) Group 1 (test2) Group 2 Group 3 Group 4 Average Control 0 0 0 0 0 0 1cm (whole)

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  20. When KMnO acts as an oxidizing agent when it comes in contact with 1 butanol, 2 butanol and t- butyl which of these agents will become primary, secondary or tertiary alcohol?

    Strong reagents will further oxidize the aldehyde into a carboxylic acid. Tertiary alcohols cannot be oxidized. The purpose of this lab was to determine the reaction of 1, 2 butanol and t- butyl when KMnO, and 2ml of acid was added to see which alcohol was primary, secondary or tertiary. Hypothesis: I believe that 1 butanol will be primary because when reacted with KMnO it will create a aldehyde and then a carboxylic acid, 2 butanol will be secondary because when reacted with KMnO it will create a ketone and then no reaction, and t- butyl will be tertiary because when reacted with KMnO it will create no reaction.

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  21. The history of the periodic table

    Gallium is considered to be an unusual element because of its properties.

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  22. In this lab, six different metals were tested for their reactivity in water. From less reactive to most reactive, the metals were as follows: Aluminum, Magnesium, Calcium, Lithium, Sodium, and Potassium

    reaction * Pink flames * Loud "crack" before it finished reacting * Sparked * Left oily layer on surface * Pink/purple * Floated on surface Discussion In this lab, six different metals were tested for their reactivity in water. From less reactive to most reactive, the metals were as follows: Aluminum, Magnesium, Calcium, Lithium, Sodium, and Potassium. A pattern found in the periodic table explaining the reactivity of metals is the further down in a family, and the further left in a period, the more reactive the metal will be.

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  23. The aim of this experiment is to investigate what affects the rate of reaction between Sodium Thiosu

    Preliminary Work I am going to obtain a number of preliminary results to find out which is the best concentration of Sodium Thiosulphate, Hydrochloric Acid and water. Preliminary Results ST (cm3) Water (cm3) HCl (cm3) Time Seconds (s) 50 0 10 28 40 10 10 45 30 20 10 62 20 30 10 100 10 40 10 239 I have decided to use a concentration of 30cm3 of Sodium Thiosulphate, 20cm3 of water and 10cm3 of Hydrochloric Acid. I have chosen to use this concentration because it enables me to obtain results from a reaction which takes about 60 - 90 seconds at room temperature which is just what I want.

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  24. Explain, giving examples from the articles, what is meant by oxidation and show how oxidation reactions are used to cause explosions. Outline reasons why some explosive mixtures oxidise faster than others.

    The power of the explosion is made greater by confining the reaction inside a restricted space e.g. Cannon. Fuels used in fireworks; Potassium Chloride (KClO3) and rockets; Hydrogen Peroxide (H2O2) are mixed with oxidisers to produce explosions. Some explosive mixtures oxidise faster than others if the reacting element(s) gains more oxygen and has a greater oxidation state. * Give an account of the development of chemical compounds for use in explosives. Describe the advantages of each new chemical explosive over its predecessors, and describe how the explosives were adapted to make them safer and more effective.

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  25. The periodic table is a chart that lists elements by atomic number and by electron arrangements

    The number of electrons in outer shell is the same as the number of the group (e.g. lithium 2�1). The blocks of elements between groups II and III are called transition metals. These are similar in many ways; they produce coloured compounds, have variable valency and are often used as catalysts. Elements 58 to 71 are known as rare earth elements. These elements are found on earth in only very small amounts. Elements 90 to 103 are known as the actinide elements. They include most of the will known elements, which are found in nuclear reactions. The elements with larger atomic numbers than 92 do not occur naturally.

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