The Solubility of Potassium Nitrate Introduction The purpose of this experiment was to observe how temperature affected the solubility of solid potassium nitrate that was put in different solvents. The temperature was not the other thing that was being varied to observe the solubility of potassium nitrate, the amount solute was also varied and the kinds of solvents in this experiment were varied. The nature of each solvent changes due to the common ion effect which is basically means that the concentration of a soluble salt is reduced if there is a common ion with that salt. Also potassium nitrate solubility in basic and acidic places was also determined, to see if it affected the temperature. The moles of KNO3 s/ Kg solvent were needed to calculate the correct molal concentration.
Titration lab report Chemistry unit 3 Abstract In this investigation it was looked at the titration of HCL with NaOH, this is a neutralization reaction that is performed in lab in order to determine an unknown concentration of acid (HCL). In this investigation the moles and concentration of acid as well as the Ph of the solution were find out, the mole of 25ml of HCL was 0.65, concentration was 0.026 and the Ph of solution was 1.58Ph. Introduction Titration is a process to measure the volume of an end product, which is produced by reacting a solution of known concentration with a measured volume of a solution of an unknown concentration. The known concentration solution is called a standard solution, it will be added from a buret to allow measure the amount of solution which is added. The solution that is added by buret also called titrant.
Determination of the pKa of Methyl Red by UV-Vis Spectroscopy February 16, 2010 (Partner:) ABSTRACT The purpose of this experiment was to obtain the pKa for an acid-base indicator. A spectrometer was used to determine the pKa of methyl red. The calibration curves were created by analyzing samples of known concentration at pH’s well above and below the pH indicator range for methyl red. Then samples of known pH were analyzed. By, solving the system of equations using linear algebra, the concentrations of the indicator and the conjugate base were determined.
The apparent reaction rate was calculated using the equation, kapp= (1/∆t) x ([S2O32-]/[S2O82-]) which resulted in apparent rate constants of 5.66 x 10-5 s-1, 6.1958 x 10-5 s-1, 6.0356 x 10-5 s-1. The actual concentration was calculated using the basic chemical equation, C1V1 = C2V2. In order to find the order of reaction a a graph of log rate vs. log [S2O82-] was drawn, and was found that the results gave a zero order reaction But in reality the reaction order in [I-] and [S2O82-] is in first order each, although [I-] is kept at a constant volume throughout the reaction therefore the overall reaction is pseudo- first order. -d [S2O82-] = kapp [S2O82-] Dt In the second part the rate constant was found using the equation k = (1/∆t) x ([S2O32- ]/[Iodine][S2O82-]). Where it resulted to values of 3.990602 x 10-3 s-1, 4.653278 x 10-3 s-1, 5.944044 x 10-3 s-1, 7.499958 x 10-3 s-1, 7.499958 x 10-3 s-1, 9.84554 x 10-3 s-1, for flasks 4, 5, 6, 7, 8.
TITRATION OF AN ACID (A PREPARED STANDARD SOLUTION OF KH₅O₄C₈) AGAINST A BASE (NAOH) USING PHENOLPHTHALEIN AS AN INDICATOR BY GRACE The aim of this experiment is to prepare a standard solution of potassium hydrogen phthalate (KH₅O₄C₈) and then use it to calculate the concentration of sodium hydroxide by titrating the acid (KH₅O₄C₈) against the base (NaOH). Before the whole experiment could take place, some apparatus were needed which included the following; A weighing balance, burette, pipette, a conical flask, clamp and then the setup was as below; THEORY To calculate for the moles of KH₅O₄C₈, I used n (mol) =m (g)/M (gmol⁻ⁱ (JOHN GREEN AND SADRU DAMJI, PG 6 OF CHAPTER 1.THIRD EDITION). Whereby m=mass of the acid, M=molar mass of the acid and n=number of moles. Molar mass of KH₅O₄C₈ is 204.1g/mol and its mass is 1g Therefore=1g/204.1gmol⁻ⁱ n=0.0048996mol Further more, to calculate for the concentration of the acid, I used C(moldm⁻3.) =n (mol)/v (dm3) Whereby c=concentration, n=number of moles and v=volume used.
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.
Titration is an operation of a common laboratory method of quantitative chemical analysis, which determines the unknown concentration of a substance in a solution by adding to a standard reagent of known concentration, this is also known as volumetric analysis. In this case C1V1= C2V2 equation was used. pH is defined by the following equation; pH= -log10H+. pH is measured by the amount of H+ ions in the solution in comparison to OH- ions; therefore, a solution with the higher pH will contain higher concentration of OH-. A solution with a pH of 7 would be neutral, while an acidic solution would have a pH of lower than 7.
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.
Diprotic Acid Abstract: In this experiment, the total amount of acid neutralized by a solution containing both Na2CO3 and NaHCO3 was determined followed by using the information to calculate the concentrations of carbonate and bicarbonate ions in the solution. This was done by equipping LoggerPro with a pH sensor and a drop counter in order to calculate the pH levels after every single drop. Three titrations were performed for analysis: a titration of a known acid with Bromothymol blue indicator, a titration of an unknown acid with Bromothymol indicator, and a titration of an unknown acid with phenolphthalein. The indicators were added for comparison between color indicators and pH titrations. The results showed that the concentration of Na2CO3 in the unknown acid is between 0.03152M and 0.03924M, and the concentration of NaHCO3 is between 0.02148M and 0.02924M.
Experiment 8 : Ramen Spectroscopy Objective: To utilize Raman Spectroscopy as an analytical chemistry tool to determine (i) the composition of an unknown chloroform/benzene mixture (ii) the amount of ethanol in vodka. Pre-lab questions: 1) What is a calibration curve and how would you go about constructing one? A calibration curve shows the response of an analytical method to known quantities of an analyte. To construct a calibration curve, we first prepare known samples of the analyte covering a range of concentrations expected for the unknowns and measure the response of the analytical procedures of these standards to generate signal data. After the measurement is done, a linear graph of the signal data against analyte concentration is plotted.