...Rate of Reaction The rate of a reaction is the speed at which a chemical reaction happens. If a reaction has a low rate, that means the molecules combine at a slower speed than a reaction with a high rate. Some reactions take hundreds, maybe even thousands, of years while others can happen in less than one second. If you want to think of a very slow reaction, think about how long it takes plants and ancient fish to become fossils (carbonization). The rate of reaction also depends on the type of molecules that are combining. If there are low concentrations of an essential element or compound, the reaction will be slower. There is another big idea for rates of reaction called collision theory. The collision theory says that as more collisions in a system occur, there will be more combinations of molecules bouncing into each other. If you have more possible combinations there is a higher chance that the molecules will complete the reaction. The reaction will happen faster which means the rate of that reaction will increase. Think about how slowly molecules move in honey when compared to your soda even though they are both liquids. There are a lower number of collisions in the honey because of stronger intermolecular forces (forces between molecules). The greater forces mean that honey has a higher viscosity than the soda water. Factors That Affect Rate Reactions happen - no matter what. Chemicals are always combining or breaking down. The reactions happen over and...
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...GCSE DOUBLE AWARD SCIENCE INVESTIGATION Title: Investigating how concentration changes the rate of a chemical reaction | Name: Ryan Bradley | Class: 12A1 | What is the aim of this experiment? To investigate how concentration hydrochloric acid affects the rate of reaction between sodium thiosulphate and hydrochloric acid and water. P.6a: List all the factors that could have an effect on the results in this investigation? * Concentration * Temperature * Surface area * Catalyst * Colour of the X * Stirring the mixture * Water in the beaker from washing out beaker P.6a: P.8a: Explain in detail how each of the factors you named could affect the investigation? Surface Area: This would affect my investigation because if there was a bigger surface area this means the particles have more room to collide as they are more exposed to head on collisions Concentration: If I was to increase the concentrations of the hydrochloric acid by too much/ little this will make my results unreliable because the more hydrochloric acid the more successful collisions and this would increase the rate of reaction. Stirring the mixture: This would affect my investigation because if I was to stir the mixture it would speed up the reaction time as you are creating more collisions meaning the ‘x’ will disappear quicker. Temperature: If I was to increase the temperature this would affect my investigation because it would mean the particles would gain more energy and this would...
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...the effect that enzyme concentration has on reaction time and the effect that substrate concentration has on enzyme reaction. Enzymes are biological catalysts that catalyze different chemical reactions. In general, enzymes are proteins and they are each specific to specific chemical reaction. In order for enzymes to process properly, they should maintain a specific three dimensional structure. When enzymes function, they combine with their substrates (reactant) to form susbtrate-enzyme complex. Then this complex converts into a product and unaltered enzyme. Substrate + Enzyme Substrate-Enzyme Complex Product + Enzyme OR Substrate –Enzyme Product (From this equation, in general, the reaction of enzyme is irreversible.) Some of the factors that affect the rate of reaction are temperature, pH, enzyme concentration, substrate concentration, product concentration, etc. The rate of reaction is affected by the level of pH. The extreme level of pH can denature enzyme and result loss of its action. The optimum pH is 14 and this is the level of pH where the rate of reaction is the highest. Temperature also affects the rate of reaction. As temperature increases, the rate of reaction increases as well; however, it increases until the optimum temperature. After optimum temperature, the enzyme denatured. The concentration of enzyme and substrate affect the rate of reaction. In theory, the higher the concentration of substrate, the faster the reaction rate processes. This is because...
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...Enzymatic Reaction of Sucrose and Sucrase: Analysis Under Different Conditions and Concentrations Abstract: Sucrase is the enzyme that breaks down sucrose into glucose and fructose. The purpose of this lab experiment was to determine under what environment the enzymatic reaction between sucrose and sucrase would produce the most products and the rate of production. To determine the rate of reaction, Benedicts Reagent was used to identify the amount of glucose produced from the enzymatic reaction. Benedicts Reagent is used to detect the presence of glucose and indicates the results with varying degrees of color. We were successful in our endeavors to measure this rate of reaction with Benedicts Reagent and conclude that the higher the substrate or enzyme concentration, the faster the rate. The process of using Benedicts Reagent to measure glucose levels is also used in urine analysis for people with diabetes. Introduction: All living organisms need to supply themselves with nutrients and as humans, we use the process of digestion to break down and extrapolate the nutrients from our food to maintain and fuel our bodies. In order to perform digestion our bodies use enzymes, which are biological catalysts. They are made of proteins that responsible for the chemical reactions essential to sustaining life. Enzymes have three major characteristics: increase the rate of reaction, are substrate specific and lower the energy barrier it takes to for reactants to occur...
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...Chemistry Coursework : Rates of Reaction Chemistry Table of Contents Table of Contents 1 Strand Sa 2 The Science 2 Variables 2 Temperature 2 Concentration 2 My Prediction 3 Strand Sb 3 Risk Assessment. 3 Preliminary Equipment 4 Preliminary Method 6 Strand C 7 Preliminary Data 7 Main Method 8 Main Results. 9 Strand Ea 9 Problems Encountered when collecting data. 9 Alternate Methods 10 Light Meter 10 Gas Collection 10 Strand Eb 11 Data Analysis 11 Graph Evaluation 11 Strand Ra 12 Secondary Data 1 12 Secondary Data 2 13 Secondary Data 3 14 Strand Rb 15 Conclusion 15 Bibliography 16 Strand Sa The Science In the experiment, I will be testing how increasing the concentration of the reactant affects the rate of reaction between hydrochloric acid and sodium thiosulfate .Due to Max Trautz’s collision theory, which states that the higher the concentration of the reactant raises the number of collisions, I predict that the less dilute sodium thiosulfate solution will have a higher reaction rate than that of a lower concentration of sodium thiosulfate. The formula for the reaction is: HCl(aq) + Na2S2O3(aq) NaCl(aq) + SO2(g) + S(s) + H2O(l). The formula shows us that the sulphur precipitate is formed along with water, sodium chloride and sulphur dioxide. Sulphur dioxide is a poisonous gas and so extra care will be taken not to inhale any. Figure 1 [18] Variables The Variables that affect the reaction rate of sodium thiosulfate...
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...20/9/2013 How Substrate Concentration affects a Catalase Enzyme Reaction RQ How does changing the substrate concentration affect the rate of a catalase reaction in an enzyme? Hydrogen peroxide was used as the substrate and the rate was measured by oxygen production. Hypothesis If the substrate concentration is increased then the rate of a catalase reaction will also increase until it reaches the optimal concentration or saturation point and will remain constant. This is because there will be more substrate molecules in a higher concentration therefore a higher frequency of collisions. This increases enzyme activity and more product will be formed. However at a certain concentration the enzymes will become saturated (all active sites are full), so an increase in substrate molecules will stop affecting the rate. Variables Independent Variable - Hydrogen peroxide concentration Dependent Variable – rate of catalase reaction by measuring the volume of oxygen produced after five minutes Controlled Variables – performed at room temperature (21 Celsius), catalase used (potato), weight of potato (1g) in each trial, time given for reaction to take place (5 minutes), method & apparatus Apparatus 1. Safety goggles & apron 2. Measuring cylinder, 100 cm3 (+/- 0.5cm3) 3. Large plastic tub 4. Access to sink/water 5. Clamp stand, boss and clamp 6. Rubber bung and delivery tube 7. 9 large test tubes 8. Stopwatch (+/- 0.01s) 9. Hydrogen Peroxide, range of concentration: 1%, 3%...
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...Lydia Thomas- biology Describe and explain how different factors affect the function of enzyme catalysed reactions (inhibitors not required) (10) There are four main factors that affect the rate of reaction on enzyme-catalysed reactions. The first of these is temperature. When increasing the temperature of a reaction the kinetic energy of molecules increases and therefore they more around more quickly and collide with each other more often. This means that within an enzyme-catalysed reaction the substrate molecules collide more often with an enzyme and so the rate of the reaction increases. When the temperature reaches a certain heat that is beyond the enzymes optimum temp the hydrogen bonds within the enzyme vibrate more rapidly and start to break. This in turn alters the shape of the active site so that the substrate no longer fits. The rate of reaction at this point then slows down as there are less enzyme-substrate reactions. Another factor that can affect the function of an enzyme-catalysed reaction is that of pH. Most enzymes have an optimum pH at which the rate of reaction is at its maximum. Small changes in this pH can cause reversible changes in the enzyme structure and can result in inactivation, although large changes may denature the enzyme entirely. A change in the pH means that the active site of the enzyme becomes wrongly charged. This means that at a high or low pH the active site will repel the substrate. It is the amino acid side-chains of the enzymes...
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...Chapter 3 Enzymes Learning Outcomes Candidates should be able to: (a) explain that enzymes are globular proteins that catalyse metabolic reactions; (b) explain the mode of action of enzymes in terms of an active site, enzyme/substrate complex, lowering of activation energy and enzyme specificity; (c) [PA] follow the progress of an enzyme-catalysed reaction by measuring rates of formation of products (for example, using catalase) or rates of disappearance of substrate (for example, using amylase); (d) [PA] investigate and explain the effects of temperature, pH, enzyme concentration and substrate concentration on the rate of enzymecatalysed reactions; (e) explain the effects of competitive and non-competitive inhibitors on the rate of enzyme activity; (f) use the knowledge gained in this section in new situations or to solve related problems. Enzymes are globular protein which act as catalysts • Enzymes are protein molecules defined as biological catalysts which speed up a chemical reaction and remain unchanged at the end of reaction. • Enzyme names end in –ase E.g. amylase, ATPase • Enzyme are globular proteins. Enzymes are globular protein which act as catalysts • Enzyme molecules are coiled into a precise threedimensional shape, which hydrophilic R groups (side-chains) on the outside of the molecule ensuring that they are soluble. Enzymes are globular protein which act as catalysts • Enzyme molecules have active site. • The active site of an enzyme is a region...
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...ratio of [pic] decreases A. I and II only B. I and III only C. II and III only D. I, II and III (Total 1 mark) 2. Which statement about chemical equilibria implies they are dynamic? A. The position of equilibrium constantly changes. B. The rates of forward and backward reactions change. C. The reactants and products continue to react. D. The concentrations of the reactants and products continue to change. (Total 1 mark) 3. Methanol may be produced by the exothermic reaction of carbon monoxide gas and hydrogen gas. CO(g) + 2H2(g) [pic] CH3OH(g) ∆HO = –103 kJ (a) State the equilibrium constant expression, Kc, for the production of methanol. ...................................................................................................................................... ...................................................................................................................................... (1) (b) State and explain the effect of changing the following conditions on the amount of methanol present at equilibrium: (i) increasing the temperature of the reaction at constant pressure. ........................................................................................................................... .............................................................................................................
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...The Effects of Temperature, pH, Enzyme Concentration , and Substrate Concentration on Catecholase Introduction Enzymes are biological proteins that speed up the reaction rate of a chemical reaction. They work in the human body by lowering activation energy making certain that reactions will initiate. For every action, there is an equal and opposite reaction. In this case, factors that influence the activity of an enzyme are called modulators. If modulators activate enzymes the reaction rate catalyzed will significantly increase, but if the modulator inactivates enzymes the reaction rate catalyzed will significantly decreased (Silverthorn, 2004). The potentially disastrous influence of temperature, pH, enzyme concentration, and substrate concentration on enzymes and other proteins is one reason why these modulators are very strictly regulated by the body (Silverthorn, 2004). Temperature, a measure of the intensity of heat, is an important factor in the activity of enzymes. The velocity of an enzymatic reaction is influenced by temperature. This is because substrates collide with active sites frequently in the presence of rapidly moving molecules. In addition, although these molecules do move rapidly the speed of the reaction drops sharply. In short, thermal agitation causes protein molecules (enzymes) to denature ( breakdown of protein structures). All enzymes have an optimal temperature at which reaction rates go fastest without denaturing the enzyme (Campbell and Reece, 2002)...
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...Title: Enzyme Introduction The main reason for conducting this experiment is to establish the various factors that affect enzymes and reaction rates. Various experiments have been conducted to help gain a wide range of the factors that affect enzyme controlled reactions. Enzymes are affected by very many factors. It was the main aim of this experiment to establish these factors and the manner in which they affect them. This experiment also seeks to establish the manner in which some enzymes like Catalase affect the rates of reactions (Cohnheim 2009). Methods To establish the factors that affect enzymes, the procedures for the experiments to be carried out had to be almost perfect. For this reason the apparatus to be used had to be cleaned thoroughly just before commencing the experiment. To avoid differentiated results, similar kinds of apparatus were used all through the experiment. In this case glass test tubes were used. Also measuring apparatuses used were of the same size and volume. In this case four experiments were carried out. The first experiment is to establish the manner in which the enzyme Catalase affects reaction rates. The procedure of this experiment is as follows; using a pencil, label tree test tubes as test tube 1, 2 & 3. On these test tubes, label two marks using the pencil. These are at the 1cm mark and at the 5 cm mark. For the first test tube, pour in Catalase enzyme up to the first mark and add Hydrogen Peroxide up to the...
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...A Kinetics Experiment The Rate of a Chemical Reaction: A Clock Reaction Andrea Deoudes February 2, 2010 Introduction: The rates of chemical reactions and the ability to control those rates are crucial aspects of life. Chemical kinetics is the study of the rates at which chemical reactions occur, the factors that affect the speed of reactions, and the mechanisms by which reactions proceed. The reaction rate depends on the reactants, the concentrations of the reactants, the temperature at which the reaction takes place, and any catalysts or inhibitors that affect the reaction. If a chemical reaction has a fast rate, a large portion of the molecules react to form products in a given time period. If a chemical reaction has a slow rate, a small portion of molecules react to form products in a given time period. This experiment studied the kinetics of a reaction between an iodide ion (I-1) and a peroxydisulfate ion (S2O8-2) in the first reaction: 2I-1 + S2O8-2 I2 + 2SO4-2. This is a relatively slow reaction. The reaction rate is dependent on the concentrations of the reactants, following the rate law: Rate = k[I-1]m[S2O8-2]n. In order to study the kinetics of this reaction, or any reaction, there must be an experimental way to measure the concentration of at least one of the reactants or products as a function of time. This was done in this experiment using a second reaction, 2S2O3-2 + I2 S4O6-2 + 2I-1, which occurred simultaneously with the reaction under investigation. Adding...
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...What did caffeine and ethanol do to the heart rate of Daphnia? Increasing the concentration of ethanol in Daphnia decreases heart rate. Increasing the concentration of caffeine in Daphnia increases heart rate. Independent vs. Dependent Variable Independent Variable: One or more factors that the scientist varies during the experiment. Dependent Variable: A feature that the scientist measures in order to determine if it changed in response to the independent variable. What solutions were used to test for the 4 types of organic molecules? Iodine- Polysaccharide Benedict’s Reagent- Sugar Biuret Test- Protein Brown Paper Test- Lipids Vegetable Oil- Solubility of Lipids What does a positive test look like? -Iodine test for polysaccharide: dark purple/black/blue -Vegetable Oil test for solubility of lipids: 1 layer -Biuret test for protein: violet color -Benedict’s Reagent for sugar: very high concentration/orange-red How do you convert Celsius to Fahrenheit and vise versa? ...
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...Introduction: Often times when we think of acids and bases we recognize acids and bases by their simple properties, such as taste. We know that a lemon is sour, so it is acidic. Bases tend to taste bitter. However, when working in laboratory chemists cannot rely on their taste buds to predict the result of the many reactions they encounter. It is important to know the classification and the formula of acids and bases in order to understand how one substance will react with another. In this lab we observed how acids and bases change the color of certain dyes, such as litmus. We also observe the solubility of certain salt compounds. When solids dissolve in water, they dissociate to give the elementary particles from which they are formed. As a result, ionic solids dissociate to give solutions of the positive and negative ions they contain. Experiment Please refer to Report Sheet Calculations Please refer to Report Sheet for pH values of acid bases and salts utilized in the lab experiment Reaction of Salt mixtures FeCl3 + CoCl2 ( FeCl2 + CoCl3 Complete: Fe3+ + 3Cl- + Co2+ + 2Cl- ( Fe2+ + 2Cl- + Co3+ + 3Cl- Net: Fe3+ + Co2+(Fe2+ + Co3+ CoCl2 + Na2CO3 ( CoCO3 + Na2Cl2 Complete: Co2+ + 2Cl- + 2Na+ + (CO3)2- ( CoCO3 + 2NA+ + 2CL- Net: Co2+ + CO3 2- ( CoCO3 CuSO4 + Na2CO3 ( CuCO3 + Na2SO4 ionic: Cu+2 + SO4-2 + Na2+1 + CO3-2 ( CuCO3 + Na2+1 + SO4-2 Net: CO3- + Cu+ ( CuCO3 CuSO4 + Na3PO4 ( Cu3(PO4)2+Na2SO4 Complete:Cu+2 + SO4-2 + 6Na+ PO4(3-)+2...
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...Temperature on Rate of Reaction of Catalase Abstract Properties of Enzymes focused on the variations of reaction rates amongst enzymes subjected to various circumstances such as temperature, pH levels, different concentrations of substrate, salt concentrations, Metal Copper Sulfate and lastly, the presence of an Enzyme Inhibitor. The assigned section of this laboratory for our efforts was the effect of temperature variations on enzyme reactions. To perform the experiment, we used a spectrophotometer to monitor the baseline catalase activity when they are placed in these two temperatures. In this way, absorbance can be measured over time to monitor catalase activity of the main baseline reaction. Our results showed that temperatures at higher degrees led to being inactive, whereas those at lower degrees lowered the reaction time. This comes to show that each enzyme can have a different optimal temperature and this experiment helped us to understand how reaction rate can be affected by temperature change. Introduction Thousands of complex biological processes are constantly taking place within our bodies. We require material transport, energy synthesis, and the manufacturing of various proteins, hormones, and other molecules (Source 1). Almost all of these everyday processes rely on the function of enzymes to take place. Enzymes are specifically grouped according to their function, and this information can often provide us with clues regarding what type of reaction that enzyme...
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