Rates of Reaction- Hydrolysis of Urea by Urease
The Effects of Temperature and pH on the Hydrolysis of Urea by Urease By Justine Hyu Abstract: The relationship and effect of both temperature and pH, on the enzyme urease was investigated. This was accomplished by initiating the hydrolysis of urea by urease in different variables in order to show changing enzyme activity. Several theories which involved the optimum conditions of urease were explored during the experiment, and in effect were highly involved with the modelling of the experiment. Many expected results were obtained, some of which applied to the researched theories. However, although this experiment was functional there, overall, improvements and adjustments could be made to enhance accuracy. Aim: The aim of this experiment is to investigate the optimum temperature and pH of the enzyme urease, and to show the diverse effects of both variables. Hypothesis: As the temperature increases, urease enzyme activity will rapidly increase until reaching its maximum potential of 50°C, where the rate of reaction is at a peak. After this point the enzyme will denature and become inefficient. Urease will be less active in acidic and basic environments but will work most efficiently in more neutral surroundings; meaning that urease will be less active in a solution of a low pH and high pH, but at a neutral pH of 7 it will function at its best. Introduction and
An investigation into the factors that affect The rate of reaction between Sodium Thiosulphate & Hydrochloric Acid
An investigation into the factors that affect The rate of reaction between Sodium Thiosulphate & Hydrochloric Acid AIM: to investigate into the factors that affect the rate of reaction between Sodium Thiosulphate & Hydrochloric Acid. APPARATUS: 50ml Sodium Thiosulphate 0ml Hydrochloric 00ml conical flask distilled water Laminated paper with a x on it Measuring cylinder Stop watch Pipette DIAGRAM: ok this is more or less what my coursework was like i made quite a few changes but hey thats life. hope you find it useful and i will remember this when were at KES! PLAN: there are many factors that could change the rate of reaction- temperature of the liquids, concentration of the liquids, adding a catalyst, the size of particles if one part was a solid. I have chosen to change the concentration of Sodium Thiosulphate each time for the experiment. This is because I feel it is the easiest to do with the time and apparatus available. I am changing the concentration of Sodium Thiosulphate and not the Hydrochloric Acid because there is more volume of Sodium Thiosulphate. I will make up the concentrations of the Sodium Thiosulphate- 0.25 mol dm-3, 0.23 mol dm-3, 0.2 mol dm-3, 0.18 mol dm-3, 0.15mol dm-3, 0.13 mol dm-3 and put them in test tubes. I will measure out the Hydrochloric acid (10ml) and pour it the conical, which is on top of the laminated paper with a
Disappearing cross (aka Rate of reaction).
Science Coursework Disappearing cross (aka Rate of reaction) Introduction This experiment is to investigate is two liquids, heated to an increasing temperature to see if it will make a reaction take place faster. The experiment I have used is the disappearing cross experiment, where two liquids, sodium thiosulphate and hydrochloric acid are mixed together and eventually the solution will become cloudy. I am going to investigate temperature in both of the liquids, heating them both to the optimum temperature before they are combined. The cross will be hand-drawn on paper and made water proof by covering it with sticky tape, due to it being underwater during the experiment. Once I have all the equipment in place I will mix the two liquids and measure the amount of time it takes for the solution to become cloudy. I will repeat this experiment 3 times to allow my results to be as accurate as possible. Each solution will have 10ml of sodium thiosulphate and 10ml of hydrochloric acid. The chemical reaction formula is: Na2S2O3 (aq) + 2HCL (aq) 2Nacl (aq) + H2O (l) + S (s) + SO2 (g). As a word equation that would be: Sodium Thiosulphate + Hydrochloric Acid Sodium Chloride + Water + Sulphur 4r2
To measure the rate of reaction of thiosulphate ions with acid in solution, and find out how the rate of reaction depends on the concentration of both thiosulphate and acid.
Chemistry - CH2 Practical Assessment Written Account of Practical Assessment Aim: To measure the rate of reaction of thiosulphate ions with acid in solution, and find out how the rate of reaction depends on the concentration of both thiosulphate and acid. Hypothesis & Prediction: We will place the reaction vessel over a black cross, drawn on a white background. The black cross will disappear from view, owing to the increased sulphur concentration in the solution, when a fixed amount of reaction has taken place. I predict that the time taken for this fixed amount of reaction is directly proportional to the rate of reaction; that is, if the reaction is fast, the cross will disappear quickly and vice versa. The more concentrated the reagents, therefore, the faster the reaction will be. Background Information & Knowledge: Reactions can only happen when the reactant particles collide, but most collisions are not successful in forming product molecules. The reactant molecules must collide with enough energy to break the original bonds so those new bonds in the product molecules can be formed. All the rate-controlling factors are to do with the frequency of reactant particle collision. If the concentration of any reactant in a solution is increased, the rate of reaction is increased. Increasing the concentration increases the probability of a collision between reactant
The reaction between Calcium carbonate and Hydrochloric acid.
Year 10 chemistry coursework The reaction between Calcium carbonate and Hydrochloric acid Introduction There are six things that affect the reaction between calcium carbonate and hydrochloric acid. They are: * The temperatures of the acid * The amount of acid * The concentration of the acid * The surface area of the calcium carbonate * The amount of calcium carbonate * The form of calcium carbonate. (It is available in three forms: powder, small stones or large stones) I have decided to investigate how the concentration of the hydrochloric acid affects the reaction rate between them. What I will need/Equipment list * Large marble (calcium carbonate) chips * Hydrochloric acid (2molar) * Water bath * Measuring cylinder * Beaker with bung and gas tube * Stopwatch * H2O * Scales Preliminary Experiment To see what happens between calcium carbonate and hydrochloric acid when they react together I shall carry out some preliminary experiments CaCO3(s) + 2HCl(aq)= CaCl2 (aq) + H2O(l) + CO2(g) I shall conduct my preliminary experiments at five different concentrations. Preliminary results Concentration (%) Concentration Amount (CM3) Gas In 1 Minute (CM3) 00 50 45 80 40 34 60 30 28 40 20 22 20 0 4 Diagram Below is a labelled diagram of the experiment Background knowledge Key Variables * Surface area of solid - The surface area has an
A discussion on Catalysis.
Catalysis Catalysis is alteration of the speed of a chemical reaction, through the presence of an additional substance, known as a catalyst that remains chemically unchanged by the reaction. A catalyst in a solution with or in the same phase as the reactants is called a homogeneous catalyst. The catalyst combines with one of the reactants to form a compound that reacts more readily with the other reactants. The catalyst, however, does not influence the equilibrium of the reaction, because the decomposition of the products into the reactants is speeded up to a similar degree. An example of homogeneous catalysis is the formation of sulphur trioxide by the reaction of sulphur dioxide with oxygen, in which nitrogen dioxide serves as a catalyst. 2SO2(g) + O2(g) › 2SO3(g) NO2(g) A catalyst that is in a separate phase from the reactants is said to be a heterogeneous, or contact, catalyst. Contact catalysts are materials with the capability of adsorbing molecules of gases or liquids onto their surfaces. An example of heterogeneous catalysis is the use of finely divided platinum to catalyse the reaction of carbon monoxide with oxygen to form carbon dioxide. This reaction is used in catalytic converters mounted in automobiles to eliminate carbon monoxide from the exhaust gases. Some substances, called promoters, do not have catalytic ability by themselves but increase the
Investigating how changing the concentration of hydrochloric acid affects the rate of its reaction with magnesium metal.
Investigating how changing the concentration of hydrochloric acid affects the rate of its reaction with magnesium metal. Introduction: During a chemical reaction, old bonds are broken and new bonds formed thus creating a new substance. In order for bonds to be broken there must be a supply of energy, however, when bonds are formed energy is released. This means that bond breaking is an endothermic reaction and bond forming an exothermic reaction. This bond breaking and forming can be done faster or slower depending on the rate of the reaction. The rate of a reaction is dependent upon the number of collisions the molecules have in any set time. This is the theory I shall be testing in this experiment. To test this I must take into consideration the factors which affect the rate of reaction. The main ones are: Concentration of the reactants, for instance if I had a lower amount of hydrochloric acid the reaction would be slower because concentration affects rate; the temperature at which the reaction takes place, for example most reactions happen quicker at higher temperatures but if I was experimenting with an enzyme the reaction would work best at a certain temperature like 37?c for body enzymes; surface area of the magnesium, i.e. whether I will keep it in one large piece or cut it into evenly sized smaller pieces so I may cover a larger
Working with calculus Assignment 1 Nose bleed
AS Use of Maths Working with calculus Assignment 1: Nose bleed! The nightmare has come to pass. All of Kelley's extensive surgeries and nasal passage scrapings have (unfortunately) gone awry, and he waits in the Ear, Nose, and Throat doctor's office waiting area spewing bloody snot into a conical paper cup at the rate of 4 in3/min. The cup is being held with the vertex down (all the better to pool the snot in, my dear). The booger catcher has a height of 5 inches and a base of 3 inches. How fast is the mucous level rising in the cup when the snot is three inches deep? Investigating the problem The volume of a cone V = where r is the radius of the cone and he is its height For the full cone or any part of it, the ratio of r:h remains fixed, so As we are only interested in the rate of change of the height we need to eliminate r so use r = 3h/10 for all levels So the new V = so to find h3 = and h = So making a table to find for t= 0 to 25 and hence work out roughly how long the cone takes to fill up, and the height value at each stage and also radius each time. As can be seen, the full height and radius is reached at about t < 15 minutes. Let's hope the doctor is on time today! Here are the formulae used to generate the table. t V h r 0 =4*A2 =(25*B2/(3*PI()))^(1/3) =3*C2/5 Here is the graph of h and r against time: Both h and r increase rapidly in the
To investigate the factors which alter the rate of the reaction.
Chemistry Coursework Aim, To investigate the factors which alter the rate of the reaction. Planning, In our experiment we will measure the rate of reaction by taking the weight of the solution every ten seconds. This may be altered as we finalise our plans. This method will give us lots of results; this will keep the accuracy of the investigation. We would like to repeat the experiment, this time measuring the rate by measuring the volume of gas given off during a period of time. This will provide lots of useful readings. But because the gas cylinder can only hold, up to 100cc of gas. This may affect the accuracy of the results. Fair Test, During the experiment the temperature of the solution will be altered but we will keep the following points the same... * ...thermometer , * ...amount of hydrochloric acid, * ...amount of limestone, * ...strength of acid, * ...sized pieces of limestone, * ...environment in which the experiment the undertaken. Prediction, I predict the experiment where we change the temperature of the solution, will react the fastest, because the particles are moving faster and will have greater effect on the limestone. Where as the concentration of acid experiment, there maybe more acid particles, but they are not moving around as fast and therefore not having as big reaction. As we increase the factor the rate will increase. I predict that
Investigate factors that effect decomposition of hydrogen peroxide.
CHEMISTRY COURSEWORK-RATES OF REACTION AIM-To Investigate factors that effect decomposition of hydrogen peroxide. The rate of a reaction is the speed at which a reaction takes place. 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 other can happen in less than one second. The rate of reaction depends on the type of molecules which are combining. HYDROGEN PEROXIDE: hydrogen peroxide is a chemical compound which is written like this H2O2, and was discovered 1818, it is a colourless, liquid that is a strong oxidizing agent. When hydrogen peroxide is placed in a water solution, it becomes a weak acid. Hydrogen peroxide can decompose to leave you with water and oxygen, this decomposition takes place when hydrogen peroxide is heated above 80°C, another way that it decomposes is in the company of catalysts, such as acids, organic materials or acids. Hydrogen peroxide has many uses in the world today. It is used in households in a water solution, as a mild bleaching agent. It is also used for medical reasons, as used as an antiseptic. Hydrogen peroxide is available for commercial use in several concentrations. During world war II, the military used highly concentrated amounts of hydrogen peroxide in fuels for things like torpedoes. Low