Phenolphthalein) is used to show the equivalence point has reached by changing colours. Titration experiments are used to determine the concentration of an acid or a base, if either acid or base concentration known, the other unknown concentration can be find out by measuring how much it takes to neutralize, which is a useful experiment. The Bronsted-Lawry theory about acid and base, describes as follows; an acid a proton (hydrogen ion) donor, a base is a proton (hydrogen ion) acceptor, or any component that can transfer proton to any other component is and acid and any component that accepts the proton is base. The theory says a substance can function as an acid only when a base is presented, and also other way round, a substance can only function as a base in the present of an acid. This theory consider a large
Molarity is the number of moles in a compound in a solution over the number of liter in the solution. In titration, solution of known quantity and concentration is enumerated to another solution of also known quantity and concentrations until an end point of combined solutions are reached. The end point is nothing really that fancy but rather an indicator of color change, which represents that the reaction is over. In the titration, the two substances exchange electrons, which can be called redox reaction. In redox reaction, one element or compound is reduced and gains electrons, while on the other hand, the other element or compound is oxidized and loses electrons.
This reaction is carried out by adding a solution of reactant hydrochloric acid from a burette to a solution of sodium hydroxide until just sufficient of hydrochloric acid has been added to react with all of the sodium hydroxide. If the concentration and volume of hydrochloric acid is known the number of moles of sodium hydroxide can be calculated, if the equation for the reaction is known. This procedure is known as a titration and the point at which sufficient volume of hydrochloric acid has been added to the sodium hydroxide to complete the reaction is called the end point. An indicator which changes colour at the equivalence point is often used to indicate the titration end point. This standardized solution of sodium hydroxide can then be used to determine the concentration of acid in the sample of gastric juice.
Chemical Kinetics: Iodine Clock Experiment Bautista, Lance Ruther E., Tornalejo, Norielle Marie B. Abstract: Is Iodine clock really a clock? In what way do we relate temperature with the rate of the reaction? How about the relationship between the concentration and rate of reaction? In this experiment, the effect of concentration and temperature on the rate of a chemical reaction will be studied. For this experiment, when the temperature increases, collision between the particles also increases.
The orders of the reaction were 2(n=m=1), k was 0.004174 L mol-1s-1 and the activation energy was 82.577kJ/mol. Introduction: Determination of orders and rate constant The reaction studied is iodide-persulfate reaction, of which the equation is showed below. 2I- + S2O82- I2 + 2SO42- The rate constant (k), and orders (n and m) of the reaction with respect to each of the reactants, in the expression for the rate of reaction R are showed below, R = k [I-]n[S2O82-]m where the square brackets indicate concentrations expressed as moles per liter. In order to determine their values, two sets of experiments need to be carried out. In the first set (part A(i)), the initial rate of reaction will be measured for different reaction mixtures in which the S2O82- concentration is held constant but the concentration of I- is varied.
Introduction: The purpose of this experiment was to determine the Activation Energy of the Hydrogen Peroxide-Iodide reaction. This was found by measuring the rate at which the reaction occurred and plotting this against the natural log of the number of moles of hydrogen peroxide remaining to find the slope. The reaction is carried out in a Potassium Iodide solution, which serves as a catalyst to the reaction. A catalyst is a chemical which increases the rate of a reaction without being consumed. Catalysts operate by decreasing the value of the activation energy for the reaction.
Measuring the rate of reaction between Sodium Thiosulphate and Dilute Hydrochloric Acid. Contents Page 1) Background Information 2) Hypothesis 3) Prediction * Independent Variable * Control Variable * Dependant Variable 4) Risk Assessment 5) Apparatus 6) Emergency Action * Method 7) Preliminary Investigation * Actual Investigation 8) Secondary Data 9) Conclusion What is rate of reaction? The rate of a chemical reaction is the time taken for the reaction to happen [1]. Reactions that have a lower rate of reaction happen slower than reactions with a higher reaction rate. It is very important that you control the rates of a reaction because both have similar reactions.
Which way will the following equilibrium shift if the total pressure on the system is decreased? 2C2H6(g) + 7O2(g) → 4CO2(g) + 6H2O(g) Answer________________ 4. Hydrogen peroxide is decomposed as follows: H2O2(l) → H2(g) + O2(g) H = +187 kJ Predict the direction of equilibrium shift by each of the following imposed changes: a) Increase the [H2] ........................................Answer ______________________ b) Decrease the [O2] .......................................Answer ______________________ c) Decrease the total pressure ........................Answer ______________________ d) Increase the temperature............................Answer ______________________ e) Add MnO2 as a catalyst.............................. Answer ______________________ 5. Consider the following reaction at equilibrium: H2(g) + I2(g) → 2HI(g) a) Addition of more H2 gas to the container will do what to the rate of the forward reaction? Answer ________________________ b) If, for a while, the rate of the forward reaction is greater than the rate of the reverse
Extended Practical Investigation The catalysis of the reaction between zinc and sulphuric acid The activation energy of the reaction will be estimated using experimental data, a catalyst will be added and the activation energies will be compared to see if the catalyst has had an effect on this. Contents Aims and objectives 3 Background 3 Preliminary experiments 4 Equipment 4 Method 4 References 5 Risk Assessment 6 Aims and objectives The effect of adding a copper catalyst to the reaction between zinc and sulphuric acid on the activation energy will be investigated. The effect of copper as a catalyst on the rate of the reaction will be observed and the Arrhenius equation will be used to calculate the activation energy. Background Acids react with some metals to produce a metal salt and hydrogen gas. Zinc reacts with sulphuric acid, producing hydrogen gas.
One of the applications of Hess' Law is to determine the enthalpy change for a reaction by combining other reactions to get the desired reaction, then combining the enthalpy changes for the reactions to get delta H for the reaction under consideration. An exothermic enthalpy change is always Assessed Practical: Planning Introduction: The aim of this experiment is to find the enthalpy change for the decomposition of sodium hydrogen carbonate. 2NaHCO = Na2CO3 + CO2 + H2O Using the enthalpy change of the following reactions. Sodium Hydrogen Carbonate: NaHCO3 + HCl = NaCl + CO2 + H2O Sodium carbonate: Na2CO3 + 2HCl = 2NaCl + CO2 + H2O Apparatus Sodium hydrogen carbonate Sodium carbonate Polystyrene Cup x 2 Measuring cylinder 50cm³ x 2 Weighing scale Weighing boats Thermometer degrees Spatula HCl acid 2M Prediction Background Information Hess' Law states that the enthalpy change for a reaction is the same whether the reaction occurs directly or in steps. This is a direct consequence of the fact that enthalpy, is a state function.