For the first beaker, we add 1 mL of 0.1 M potassium phosphate. The purpose is to test the excess of lead, and it is positive due to the presence of white precipitation. We add 1 mL of 0.1 M silver nitrate into the second beaker to test for excess iodide. It is positive due to the presence of yellow precipitation. Next, take out the filter paper and add 50 mL of water.
Distillation Experiment CHM226 Background The distillation process is a very important technique used to separate compounds based on their boiling points. A substance will boil only when the vapor pressure of the liquid is equal to the external pressure being applied by the surroundings. Distillations can be used to efficiently purify volatile (i.e. low boiling) compounds. The general concept of distillation involves the boiling of a mixture, resulting in the lower boiling compounds boiling off first.
Water is a common impurity because it is the solvent from which the acetylsalicylic acid is obtained. It would only take a small amount of water to make the melting point lower. As we have more impurities, the melting point will lower and the range of melting will become greater. A pure substance will melt with a small range of 1 to 3 °C while an impure product might melt with a range of 5 to 10 °C or more. The ferric chloride test was done to determine the purity of crystal acetylsalicylic acid.
Acid and Base Titration Aim: To determine the concentration of a dilute solution of sodium hydroxide which is approximately 0.1 mol dm-3 Introduction: Titration is an example of redox reaction and is a process of chemical analysis in which the quantity of some constituent of a sample is determined by adding to the measured sample an exactly known quantity of another substance with which the desired constituent reacts in a definite, known proportion. The process involves the gradual adding of standard solution of titrating reagent from a burette. The addition is stopped when the equivalence point is reached. From this point an exact equivalent of titrant will be added to the earlier solution. The completion of the reaction is marked by some signal; this signifies the end point.
Tablet | A report based on a scientific experiment designed to investigate and compare the rates at which different forms of aspirin dissolve. | 11-11-2013 | Introduction This experiment was designed to investigate and compare the rates at which different aspirin tablets dissolve in both Water (H2O [representing saliva]) and Hydrochloric Acid (HCl [representing the stomach’s acid]). The amount of Water and Hydrochloric Acid will be kept constant between tablets, and tests. Aim To investigate and compare the rates at which different Aspirin Tablets dissolve. The different kinds of Aspirin tablets are: * Enteric Coated Tablets * Capsules * Regular Tablets * Dissolving Tablets.
C. Write a balanced equation for the neutralization of acetic acid with NaOH. HC2H302+NaOHNaC2H302+H20 D. How would your results have differed if the tip of the burette was not filled with sodiumhydroxide before the initial volume reading was recorded? It would have shown more NaOH then there actually was resulting in there
This particular reaction is a strong acid and a strong base which means that when the reaction reaches the equivalence point, the moles of the acid and the base are equal and the solution is neutral so the pH should be around 7.0 depending on the final volume of each solution. To get this data, we will titrate an HCl solution with NaOH solution of which is a known concentration. We will record the initial and final reading of the NaOH while we record the pH of the titrated solution in the beaker. We will repeat this process with a solution of acetic acid which is a weak acid with NaOH and record the initial and final reading of NaOH and the pH of the solution in the beaker. Procedure Preview Calibrate the pH meter.
If the reaction is first order, its graphical representation is seen as ln[A] (natural log of concentration) vs. time, and the slope of its like is also the negative rate constant. Finally, for a second order reaction the graph is shown as 1/[A] (inverse of concentration) vs. time, and the slope of its given line is the positive rate constant. By understanding the rate law and finding the value of the correct rate constant with respect to the order of the reaction, one can determine the half-life of the crystal violet. This is because the crystal violet undergoes a decay reaction with the sodium hydroxide. According to Beer's Law, the absorbance of crystal violet is proportional to its concentration.
Therefore, according to Hess’s law, the heat of reaction of the one reaction should be equal to the sum of the heats of reaction for the other two. This concept is sometimes referred to as the additivity of heats of reaction. The primary objective of this experiment is to confirm this law. The reactions we will use in this experiment are: 18 - 1 Computer 18 You will use a Styrofoam cup in a beaker as a calorimeter, as shown in Figure 1. For purposes of this experiment, you may assume that the heat loss to the calorimeter and the surrounding air is negligible.
Experiment 3: Recrystallization Purposes: 1) To learn about the different types of extractions. 2) To learn to separate compounds based on their relative solubilities in two different immiscible liquids 3) To learn how to isolate the desired compound from a complex mixture. Procedure: Isolation of benzoic acid * In a Erlenmeyer flask, dissolve 50mg of unknown mixture of benzoic acid, p-nitroaniline and biphenyl in 10 ml of diethyl ether. * Add 5 ml of 6M NaOH and swirl to dissolve any residual solids. * Pour the solution into a dry, clean sep funnel.