Abstract The purpose of the experiment was to identify unknown ionic compound #. After many tests, the unknown was identified as sodium chloride. The cation (Na+) was determined by having a yellow/orange color flame test. The anion (Cl-) was determined by the chloride anion test when the unknown test solution showed a positive test for chloride. The synthesis of NaCl further identified the ionic compound by reacting sodium hydroxide and hydrochloric acid and obtaining solid sodium chloride.
Since it was inaccurate, the melting point of another group’s sample was recorded. It was determined to be 219ºC-227ºC. Results: Percent recovery=100*(weight of pure/weight of impure) Weight of Crude Caffeine | Weight of Purified Caffeine | Percent Recovery | 0.018 g | 0.015 g | 83.33% | | Started Melting | Completely Melted | Our Sample | 51 | 139 | Other Group’s Sample | 219 | 227 | Since the melting point determined was so different from the known melting point of caffeine, there must have been impurities in the sample. This is also why some of sample melted immediately while the rest took much longer. This wide melting range also indicated impurities.
Lab 4: Determination of Percent by Mass of the Composition in a Mixture by Gravimetric Analysis Introduction Thermal gravimetric analysis is used to determine the percent by mass is used to determine the percent by mass of a component in a mixture. When a mixture is heated to an appropriately high temperature, one component in the mixture decomposes to form a gaseous compound. The mass of this particular component is related to the mass of the gaseous compound. In this experiment, the percent by mass of sodium hydrogen carbonate (NaHCO3) and potassium chloride (KCl) in a mixture will be determined. Experimental First, we weighed 2 samples, each has 1 gram of NaHCO3-KCl mixture Second, we put the samples in 2 crucibles (A and B) and weighed them.
Now that we have filtered the precipitate, we will then place the resulting precipitate into a test tube to measure the weight. By using the information above in our experiment, we were then able to determine that one of these ionic compounds are not soluble in Water and in turn, produced a resulting precipitate which is the evidence that a reaction has occurred. We then identified the anion and cation for these ionic compounds. The Potassium Chromate-
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. Identify all the ionic species present in the solution before the reaction takes place. 2. Compute the molarity and the number of moles of each ionic species present before the reaction takes place. After reaction goes to completion: 3.
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 OF SULPHURIC ACID WITH SODIUM HYDROXIDE Modified: November 3, 2002 INTRODUCTION A TITRATION is a process in which a measured amount of a solution is reacted with a known volume of another solution (one of the solutions has an unknown concentration) until a desired end point is reached. (The “end point” of a titration is the point in the titration at which an indicator dye just changes colour to signal the stopping point of the titration.) In this experiment, you will use a PIPETTE to measure some sulphuric acid into a beaker. The sulphuric acid has an unknown concentration. Then you will fill a BURETTE with sodium hydroxide (a base) that has a known concentration.
Once all the equipment has be gather, step one was to clean the flask because a dirty flask might have an effect on the precise mass of it. To clean the flask, I used distilled water but before I used the water, I had to get the temperature of the water by using a Thermometer according to the experiment guidelines. After getting the temperature, I used the water to clean and then I air dried it. The next side was to weight the empty flask in record the numbers on a weighted scale. After recording the empty flask, I placed the
Stoichiometry of Reactions in Solution I. Introduction: Stoichiometry of reactions in solution applied stoichiometry and the idea of a limiting reactant to a reaction in solution. This experiment involved performing aqueous acid and base titrations to determine the mole ratios of four different acid base reactions. Titration is one compound added to a known amount of another compound quantitatively and reacted together to completion (the solution turn pink at the end point). The end point is also called the neutralization point, which means that all the acid has reacted completely with the base and the solution has been neutralized.
Required Materials: Solids: KNO3 unknown concentration, KNO3 Liquids: Tap Water, DI Water Other: 1 burette, 1 1000 mL beaker, 5 test tubes, thermometer, heating pad Objectives: • To determine the effect of temperature of the solubility of a salt. • To construct a solubility curve for the salt. • To determine the mass of an unknown size sample of the salt. Theory: Solubility is a measure of t he amount of one substance that can be dissolved in a measured amount of another substance. In this experiment we are going to measure the solubility of KNO3 in water at various temperatures.