Close Your Eyes
Close your eyes As I finished packing my suitcase I felt a tear fall onto my hand. This was the last time I'd be here. The last time I'd see this house, this room. I didn't want to leave but I had to. I'd only found out last week. Mum came home and told me over dinner that we had to move to London because she'd got a job transfer. At first I refused to leave all this behind me but after a few days it seemed like I had no choice. I'd told all my friends and they were so sad to see me go. Especially Chloe. Me and her had been best friends since we were little. We never spent a moment apart, we basically lived at each others. What's mine was hers and what hers was mine. It had always been like that. Now we were being ripped apart. It felt like I was losing a sister. I told her that I'd call her everyday and that we could talk on MSN until we fell asleep at the computer. We laughed at the idea of me living in London, after all, I hated the place, but inside we were both crying. I sat on the floor and looked around my room. The walls were bare and the wallpaper had been torn where id pulled my posters down. My bed, wardrobe, mirror, shelves, TV and every single other thing in my room was sitting inside the removal van being taken to our new home. The only thing in the room was me, and my suitcase. "Louise!" I heard mum calling me from the stairs "Darling we have to leave.
Find out how the rate of hydrolysis of an organic halogen compound depends on the identity of the halogen atom, and the nature of the carbon-hydrogen 'skeleton'.
PLANNING AIM: The purpose of this experiment is to find out how the rate of hydrolysis of an organic halogen compound depends on the identity of the halogen atom, and the nature of the carbon-hydrogen 'skeleton'. I will be comparing the rates of hydrolysis of the primary substances 1-chlorobutane, 1-bromobutane, 1-iodobutane, and will investigate the rate of hydrolysis of the tertiary substance 2-bromo-2-methylpropane. From the results I will then go on to deduce a rate expression/equation and a possible mechanism for the reaction. Calculations that are to be carried out include that of gradients and rates of the graph. This is needed because the gradient of the graph gives us the rate of reaction. A rate for each tangent taken needs to be worked out so that a rate graph can be constructed, which will give the order of the hydrolysis of the haloalkane. Example: Figure 1 (I) Rate = Gradient Gradient = Y2 - Y1 X2 - X1 = [reactants at Y2] - [reactants atY1] (where [ ] refers to the concentration) t2 - t1 (where t refers to the time) Rate = ?[reactants] (where ? refers to the change) ?t The initial rate will be taken, therefore the gradient line will start at
Effect Of Substrate Concentration On The Activity Of Catalase
Effect Of Substrate Concentration On The Activity Of Catalase Effect Of Substrate Concentration On The Activity Of Catalase AIM This is an experiment to examine how the concentration of the substrate hydrogen peroxide affects the rate of reaction of the enzyme catalase. PREDICTION I predict that as the substrate concentration increases, the rate of reaction will go up at a directly proportional rate until the solution becomes saturated with the substrate hydrogen peroxide. When this saturation point is reached, then adding extra substrate will make no difference. The rate steadily increases when more substrate is added because more of the active sites of the enzyme are being used which results in more reactions so the required amount of oxygen is made more quickly. Once the amount of substrate molecules added exceeds the number of active sites available then the rate of reaction will no longer go up. This is because the maximum number of reactions are being done at once so any extra substrate molecules have to wait until some of the active sites become available. BACKGROUND INFORMATION Enzymes such as Catalase are protein molecules which are found in living cells. They are used to speed up specific reactions in the cells. They are all very specific as each enzyme just performs one particular reaction. Catalase is an enzyme found in food such as potato and liver. It
What factors effect the rate of a chemical reaction?
What factors effect the rate of a chemical reaction Introduction During any chemical reaction the concentrations of the reactants decrease and the concentration of products increase with time. The rate of reaction (reaction velocity) may be defined as the rate of change of concentration of a stated reactant or product. The rate of a reaction is found by measuring the amount of a reactant used up per unit of time or the amount of a product produced per unit of time. A reaction can be made to go faster or slower by changing a number of factors. In order for a reaction to occur it is necessary that: particles must collide with each other and the collision must have enough energy. If this happens the original bonds are broken and new bonds are formed - so that new products are formed. Successful collisions (those with sufficient energy) can be increased (or decreased) by a number of factors. Aim I am trying to find out what factors effect the rate of a particular reaction - the reaction between Calcium Carbonate and Hydrochloric acid. Key Variables The key variables that I could change are: Surface area of solid - The surface area has an effect on the rate of reaction. If the solid has a large surface area then there are more opportunities for collisions to occur between the solid and liquid. This is because there are more opportunities for collisions to occur. If the
To investigate the effect of varying the masses of white sugar and yeast and the temperature on the rate of expansion of wheat dough.
Coursework submission for Coursework.info Planned Proposal: Aim: To investigate the effect of varying the masses of white sugar and yeast and the temperature on the rate of expansion of wheat dough. Null hypothesis: The rate of rising of dough will be independent of the mass of white sugar and yeast present in the dough and independent of the temperature. Alternate hypothesis: The rate of expansion of the wheat dough will be positively dependant on the masses of the white sugar and yeast and the dependence on the temperature will initially be positive, and then negative. Apparatus: Apparatus Quantity Purpose Weighing boat 3 Required to pour the yeast, sugar and flour being measured into for weighing on the mettler balance Mettler balance Required to accurately measure the masses of the yeast, sugar and flour Glass-distilled water 3200ml Tap water is inappropriate because it contains impurities such as mineral ions which could affect the accuracy of the experiment and introduce variables unaccounted for 25 ml measuring cylinder Required for the addition of 25ml of distilled water to dissolve the sugar. 00 ml measuring cylinder 3 was required for the addition of 75.0ml of water to the sugar-yeast mixture. The other 2 were required for measuring the rate of rise of the dough for both trials of each experiment Yeast Substance being investigated and
THE EFFECT OF BILE SALT ON THE ACTION OF THE ENZYME LIPASE
BIOLOGY A2 LEVEL COURSWORK: THE EFFECT OF BILE SALT ON THE ACTION OF THE ENZYME LIPASE NADA ISSA A2 COURSEWOEK Aim The aim of this investigation is to investigate the affect of bile salts on the action of the enzyme lipase Bile salts: Bile salts are secreted from the liver in the gall bladder, and then passed through the bile duct into the small intestine when food is passing through; they are involved in the emulsification of fats in the intestine, helping in the digestion and absorption of lipids. They also carry waste products to be excreted such as bile pigments. These derive from the breakdown of red blood cells. Bile salts are made up of a bile acid and an associated cation, which are usually amino acids. Bile salts are made up of two parts these are hydrophobic and hydrophilic components. Figure one: The above figure portrays the structure of bile acids. The hydrophobic part of the molecule associates with particles of dietary fat which causes the fat globules to break down into microscopic droplets; this increases the surface area of the fats for digestion by lipases. While the hydrophilic part associates with water which in turn emulsifies the insoluble fat, which is then absorbed through the intestinal wall. The figure illustrated below shows the action of bile salts in emulsifying fats in the intestine. Figure one: The bile acids are made from
"The Crumbling Taj".
INTRODUCTION Why should this coursework be entitled "The Crumbling Taj"? The Taj Mahal is a famous beautiful building found near Delhi in India. It is made of marble, which is a polymorphic form of calcium carbonate. Unfortunately it is slowly being damaged by acidic rain. This occurs in two forms: * Natural carbonic acid formed when carbon dioxide dissolves in water. * Acid rain made of a mixture of sulphurous acid, sulphuric acid and nitric acid. These acids are formed from pollution from the burning of fossil fuels and from the discharged exhaust from road transport. Although hydrochloric acid is not one of these mentioned, it is convenient to use in this experiment, as it is available in our laboratory. The active ion, H3O+ in all acids is present in hydrochloric acid just as much as it is present in all the other acids mentioned. AIM The aim of my investigation is to design and carry out a series of experiments to discover how the speed of chemical reaction between calcium carbonate (marble) and acid can be altered. I will be looking at the following equation: CaCO3 + 2HCl --> CaCl2 + H2O + CO2 Calcium Carbonate (marble) + Hydrochloric Acid --> CalciumChloride + Water + Carbon Dioxide The aim for my investigation is to also find out the best conditions at which the reaction rate will be at its fastest. These conditions are factors that can normally
The Effect of Catalase in the Breakdown of Hydrogen Peroxide
The Effect of Catalase in the Breakdown of Hydrogen Peroxide Aim: to give a detailed explanation on enzyme/ catalysts and an experiment to further illustrate my given hypothesis. To explain the effect of catalase as hydrogen peroxide decomposes. In addition; I must investigate Hypothesis: When catalase is the addition to an experiment, the reaction (depending on the volume of the concentration) would be a fast one. If this catalase is reacted with hydrogen peroxide, it would provide energy to produce oxygen and water. By measuring the level of the speed of the reaction, one can determine the volume of oxygen produced. The higher the oxygen amount; the faster the reaction had occurred. As the concentration is decreased, it means that the rate of the reaction would decrease. For this, I predict the higher the amount of catalase concentration added to the solution, against the substrate, the faster the rate of reaction. I also predict; as more catalase is added, more collisions occur in which more enzymes have available active sites. This is for the same reason that the higher the concentration; the quicker the rate of reaction. On the other hand; less concentration can slow down a reaction. This is due to fewer enzymes available for a reaction. In addition; I hypothesis: when more active sites are present, more hydrogen peroxide particles can bind specifically to them.
An Investigation: Factors That Affect The Rate Of Reaction between Calcium carbonate and Hydrochloric Acid
AlbinaBekteshi Chemistry coursework. Albina Bekteshi ________________ Class: Science- Chemistry Coursework ________________ An Investigation: Factors That Affect The Rate Of Reaction ________________ ________________ Due: March 14th, 2012 ________________ Contents Introduction Variables Equipment Preliminary experiment The results for the preliminary experiment. Evaluation of preliminary Justification of Method: Main experiment – changing the surface area. Results for surface area. Graphs for surface area. Conclusion Main experiment – changing concentration. Tables for concentration. Graphs for concentration. Scientific explanation Evaluation of Range Bars: Gradients Surface area Concentration - Evaluation Evaluation of procedures Evaluating data Reliability of Conclusion Introduction The rate of a reaction is a measure of how slow or fast the reaction happens. If the chemical reaction is too slow, it would be harder to see a reaction. The rate is measured from the change, which happens in a single unit of time. To find out the rate of reaction one needs to: . Look how quickly a product is formed 2. Increase the concentration 3. Work out
Experiment to investigate how changing the concentration of hydrochloric acid affects the rate of its reaction with the reactant
Experiment to investigate how changing the concentration of hydrochloric acid affects the rate of its reaction with the reactant Aim: Is to investigate how concentration of hydrochloric acid affects the rate of its reaction with the reactant. To decide which reactant I will use for my investigation, I will do preliminary experiments to decide this. Preliminary work I will be doing some different preliminary experiments. The preliminary will allow me to decide which reactants to use for my investigation and how much of that reactant to use in each experiment. Experiment 1a: Which reactant reacts best? . Display 3 beakers. In: * Beaker 1 place some chalk * Beaker 2 place some marble chips * Beaker 3 place some strips of magnesium 2. In each beaker pour some hydrochloric acid and observe the reaction. 3. Estimate the rate of the reaction on a scale of 0-5 (0= no reaction, 1= very slow, 2= slow, 3= medium, 4= fast, 5= very fast) I noted down the results, however, I realized that they are too inaccurate for me to base my decisions on them. Therefore, I will set a volume of hydrochloric acid to pour into the beakers and also I will weigh the reactants and make sure they all have the weight. Experiment 1b: Which reactant reacts best? . Display 3 beakers. In: * Beaker 1 place 2g of chalk * Beaker 2 place 2g of marble chips * Beaker 3 place 2g of strips of magnesium
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