The purpose of this investigation is to record the amount of time taken for a reaction to occur when sodium thiosulphate is mixed with hydrochloric acid. The equation for this reaction is: Na2S2O3 + 2HCl → 2NaCl + S + SO2 +H2O Sodium thiosulphate (Na2S2O3), after reacting with Hydrochloric Acid (HCl) produces yellow sulphur, which is the cause of the solution becoming cloudy. The amount of time taken for the reaction to occur is known as the reaction rate. The rate of a reaction can be commonly explained by Collision Theory. This theory states that in order for a reaction to occur, the particles of each reactant must collide together, with successful collisions resulting in chemical changes. Activation energy is released when the particles hit each other and whether the collision is successful or not is dependant on the amount of activation energy present. The energy's purpose is to allow the element to break its current bonds and form new ones. In the case of liquid solutions, the concentration of the elements is also important when considering whether the reaction will be...
The purpose of the experiment is to study the rate of reaction through varying of concentrations of a catalyst or temperatures with a constant pH, and through the data obtained the rate law, constants, and activation energies can be experimentally determined. The rate law determines how the speed of a reaction occurs thus allowing the study of the overall mechanism formation in reactions. In the general form of the rate law it is A + B C or r=k[A]x[B]y. The rate of reaction can be affected by the concentration such as A and B in the previous equation, order of reactions, and the rate constant with each species in an overall chemical reaction. As a result, the rate law must be determined experimentally. In general, in a multi-step reac...
For a reaction to occur, particles must collide. If the collision causes a chemical change it is referred to as a fruitful collision. (Hutchinson Educational Encyclopaedia, 2000) Enzymes increase the rate of exergonic reactions by decreasing the activation energy of the reaction. Exergonic reactions are those in which the free energy of the concluding state is lower than the free energy of the opening state.
The aim is to find out if changing the concentration of the hydrochloric acid solution has an effect on the time taken for the reaction. The reaction that will take place is: Hydrochloric acid + Calcium Carbonate + Calcium Chloride + Water + Carbon dioxide 2HCl (aq) + CaCo3 (s) CaCL2 (aq) + H2O + CO2 (g). Collision theory - Collisions between reactant particles are needed. for the reaction to take place in order to form a product.
From the experimental data, the [H+] decreases as the concentration of the HCl in each solution decreases. Since acids dissociate in water, the dilution of the acid’s concentration (Macid) will determine the number of free hydrogen ions in the solution, being that they are equal to each other when the -log is used. By changing the concentration of the HCl, the acid strength decreases, as shown in the change in pH, due to the presence of H+ ions as they break away from the original molecules of the acid. These free ions are in the form of hydronium ions, which shows in the decrease of the H+ in the table above.
Cations are positively charged ions, which are attracted to their negatively charged counterparts, anions. Precipitates can form when these cations and anions combine in aqueous solutions; however, precipitates only form if one of the products of the chemical reaction is not soluble in that solution. Solubility is instrumental in understanding how precipitation reactions occur. This is because solubility rules, determine whether a precipitate can form. A precipitate can form if the cation in the compound is soluble when combined with an anion. For example when the solutions silver nitrate and sodium chloride (reactants) are mixed, silver chloride and sodium nitrate (products) are formed. Following the solubility laws, silver nitrate is the precipitate, as it isn’t
However, in order to measure the rates of reaction, sodium thiosulphate and starch are added. Sodium thiosulphate is added to react with a certain amount of iodine as it is made. Without the thiosulphate, the solution would turn blue/black immediately, due to the iodine and starch. The thiosulphate ions allow the rate of reaction to be determined by delaying the reaction so that it is practical to measure the time it takes for the iodine to react with the thiosulphate. After the all the thiosulphate has reacted with the iodine, the free iodine displays a dark blue/black colour with the starch. If t is the time for the blue/black colour to appear, then 1/t is a measure of the initial rate.
The Arrhenius equation ln k = ln A – (Ea / RT) can be shown
Reactions occur when the particles of reactants collide together continuously. If they collide with sufficient energy, then they will react. The minimum amount of kinetic energy required for particles at the time of collision is called the activation energy and this theory is known as the ?collision theory?.
There are 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 solid reactants), and catalysts. I have chosen to investigate the effect of concentration on the rate of reaction. This is because it is the most practical way to investigate. Dealing with temperatures is a difficult task, especially when we have to keep constant high temperatures. Secondly, the rate equation and the constant k changes when the temperature of the reaction changes.
Effect of Temperature on the Rate of Reaction between Sodium Thiosulphate and Hydrochloric Acid Investigation Chemical reactions are used in our everyday life, they literally keep us alive. They are used in food, respiration and everywhere else in the environment. A chemical reaction mainly occurs when reactants react together to produce a new product. The speed at which this reaction takes place is called the rate of reaction. The product produced has a number of particles in the solution that has formed from the reactants.
Investigating the Effects of Temperature on the Rate of Reaction between Magnesium and Hydrochloric Acid Introduction Chemical kinetics is the study and examination of chemical reactions regarding re-arrangement of atoms, reaction rates, effect of various variables, and more. Chemical reaction rates, are the rates of change in amounts or concentrations of either products or reactants. Concentration of solutions, surface area, catalysts, temperature and the nature of reactants are all factors that can influence the rate of reaction. Increasing the concentration of a solution allows the rate of reaction to increase because highly concentrated solutions have more molecules and as a result the molecules collide faster. Surface area also affects reaction rate because when the surface area of a reactant is increased, more particles are exposed to the other reactant.
My hypothesis is that the higher the concentration the faster the reaction will take place. This is because if we have a high concentration there will be more particles in the solution than in a weaker. If there are more particles there will be more collisions. This is important as as the collision theory states, the more collisions that occur the faster the reaction will take place.
In this experiment three different equations were used and they are the Stoichiometry of Titration Reaction, Converting mL to L, and Calculating the Molarity of NaOH and HCl (Lab Guide pg. 142 and 143).
Rate of reaction is the speed of reaction. In essays written by young scientists, they have used concentration as variable in their experiments; some have used a light sensor. connected to a data logger, to measure the amount of light passing. through the "cloudy" liquid. 1 moles = 6.02 1023 The particles in the hydrochloric acid and sodium thiosulphate need to
One vital process in the human body observed in chemistry is the idea of chemical kinetics. Chemical kinetics is the study of the rate of reactions, or how fast reactions occur.1 Three factors that affect chemical kinetics are concentration, temperature, and catalysis. As the concentration of a substance increases, the rate of the reaction also increases.1 This relationship is valid because when more of a substance is added in a reaction, it increases the likelihood that the