Therefore the alkalinity of water samples is being calculated. In the second approach, the two volume readings for the respective amounts of sulfuric acid used are being determined an indicator based method. Congo red and bromocresol green are being used as the indicators. Procedure (Outline provided as pre-lab): A. The pH meter was calibrated using standard pH solutions provided.
For reaction (II) Pb (NO3)2 + 2KI -> PbI2+2KNO3 Lead nitrate is soluble, so it gets written as ions. The same goes for potassium iodide and potassium nitrate. Complete Ionic equation: 2 K+1 + I-1 + Pb2+ + NO32- -> PbI2 + 2K+1 + NO3-1 Net Ionic Equation: Pb+2 + 2 I-1 -> PbI2 Warm-Up Exercise 2 In this lab you will mix 25 mL of 0.05M lead nitrate with 1.4 mL of 0.025M sodium carbonate. After the reaction occurs, you will filter the solution to remove the precipitate. You will then test the remaining solution for excess lead ion and for excess carbonate ion… Imagine that you mix the two volumes and then freeze frame the reaction so the it does not proceed: 1.
Determination of Freezing Point and Verification of Freezing Point Depression for a Mixture by Linah Richer Partners: Maike Blakely CHM317 Preformed: Nov. 8th, 2013 Report: Nov. 19th, 2013 Abstract: The purpose of this experiment is to determine the freezing point of the solvent, biphenyl, and verify the freezing point depression equation ΔTf=-ikfnsolutemsolvent. The addition of solute will lower the vapor pressure of the solvent/solute mixture resulting in the lowering of the freezing point for the mixture solution. The experiment resulted in the experimental difference in the two trial freezing points to be 0.08 K leading to a calculated change in temperature freezing to be -1.92 E -5 K, and an overall decrease in temperature freezing of the solute/solvent solution compared to the pure solvent solution. Introduction: Experimentally it is understood that the addition of a nonvolatile solute to a solvent will lower the vapor pressure, raise the boiling point and lower the freezing point. In this experiment, the freezing point for the solvent biphenyl will be determined theoretically and experimentally, as well as the verification of the freezing point depression equation for a solvent/solute mixture.
1 mark AND Enzymes function best at their optimum pH, which in this case has been found to be (whatever their results indicate). When enzymes are acting at their optimum level the maximum amount of oxygen gas will be produced. 1 mark AND Enzymes begin to be denatured when the pH of the surrounding environment moves away from the optimum pH. The rate and extent of denaturation increases as the pH value moves away from the optimum pH. 1 mark AND Extreme pH denatures the enzyme, altering the shape of the active site and preventing the enzyme and substrate forming a complex, thereby decreasing the rate of the reactions.
Introduction A titration was carried out in this experiment to find the concentration of hydrochloric acid is an unknown solution. The aim of this experiment is to determine the number of moles of sodium hydroxide in hydrochloric acid and then to determine the number of moles of sodium hydroxide present in gastric juices. Titration, or volumetric analysis, is a common laboratory procedure for the analysis of substances and solutions. In a titration, the analyst determines the volume of a solution, called a titrant, that reacts exactly with a known weight or volume of another substance. 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.
As for endothermic the reactions pulls in energy and makes it cold to touch. The other experiment measured the pH level in the reaction. The reaction consisted of sodium hydroxide and hydrochloric acid also to see at which point the reaction becomes neutralized. Neutralization is a reaction between an acid and a base forming a salt and water even tho you can’t see the salt due to the salt dissolving into the solution and the pH level of the reaction around level 7 and has a green sometimes yellow colour when the universal indicator is added. The neutralization gap shows how small the gap is to make the reaction neutral.
Using the Primary method used to standardize the concentration of HCl, this will bring much lower percent error in the Ksp For this standardization sodium carbonate should be used for determining the amount of hydroxide in the solution. For this the equation used will be Na2CO3+2 HCl→H2O+2 NaCl The third part of this experiment uses the prepared saturated solution from part one. This part used the value for exact concentration of the HCl. Part three is done to determine the concentration of hydroxide in the solution, allowing the students to determine a value of Ksp for Ca(OH)2 completing the lab. The equation used for part three is: 2
a along a water potential gradient. At 0.05M, we still have positive numbers; however, we start to see a decrease in mass. 0.2M is where the water potential on either side of the plasma membrane is equal and so a dynamic equilibrium is established, meaning there is no net movement of water. After 0.2M, the graph starts to go into negative numbers. The loss in mass has taken place as the sucrose concentration has a low water potential, consequently the water leaves the potato tissue as it has a higher water concentration, thus the potato tissue loses mass.
The Depression of Frozen Point The boiling point and the freezing point both refer to colligative properties; in other words, the individuality of each particle is not as significant as the number of dissolved particles in a solution. In a solution, the boiling point increases and the freezing point decreases when the concentration of particles increases; this means that the change in normal boiling point as well as freezing point of water is connected to the increase of particles. Throughout the experiment, calculating the freezing point depression constant of solvent was a significant process. Observing the co-relation between the sugar concentration and freezing point was important too. In addition, the freezing point of the same solution for sugar and salt was compared.
Introducation. The reaction rate rarely measured directly using differential rate law because of the difficulty in determining accurate values of slope. Instead integrated rate laws used which expresses kinetics behaviour directly in terms of measurable observables of concentration and time. The integrated rate laws is simple and the advantage of using of it is that order of reaction with respect to a given reactant is readily tested by means of the appropriate plot of reactant concentration against time. The isolation method is a common method of simplifying the rate law when more that one reactant is involved is to arrange for all the reactants except one to be present in such large excess that their concentration can be regarded as remaining effectively constant throughout the reaction.