Objective To determine of heats from three exothermic reactions and investigate the Hess Law Summary Based on this experiment, we have study three related exothermic reactions involving sodium hydroxide. The first reaction (Part A), solid sodium hydroxide will dissociate into water. The heat produce by this reaction (∆H1) and this called as the heat of solution of solid NaOH. From the experiment we have managed to determined that ∆H1 = -41.84 KJ/mol In the second reaction (Part B), an aqueous solution of NaOH is allowed to react with an aqueous solution of HCl. This is a neutralization reaction between a strong acid and strong base.
Sodium Hydroxide + Hydrochloric Acid Sodium Chloride + Water NaOH(aq) + HClaq → NaCl(aq) + H2O(l) Variables Independent The independent variable of the experiment was the amount of sodium hydroxide that we added to the acid. To keep the variable controlled we would measure 1 ml of the sodium hydroxide and pouring that to the hydrochloric acid. Dependent The dependent variables of the experiment were the temperature and the pH number of the mixture. To control the pH and temperature use the electronic probe and data logger. Controlled The controlled variables of the experiment were: A.
In this experiment we will determine the percent composition of the NaHCO_3 and the contaminates in the solution. Experiment 1 – Titration of NaHCO_3 with HCl. Titration allows for the equilibration of the unknown substance with an acid. The amount of acid required to neutralize the unknown will give data on the amount of base present. The titration between NaHCO_3 and HCl will determine the percent composition of NaHCO_3 in the Athenium Baking Soda.
Identification of Copper (II) Chloride Introduction Through a series of cation and anion confirmation and elimination tests, the identity of an unknown compound can be determined. By subjecting certain standards to a series of tests, it will be known how they react when trying to identify the unknown. The results of these tests are crucial to correct identification of the unknown compound. Materials and Methods 0.5 grams of the unknown 11 was added to 5 mL of distilled water in a centrifuge tube to make the stock solution. To determine the cation, 6 M NaOH was added dropwise to the unknown solution until a precipitate was formed.
ISOPENTYL ACETATE SYNTHESIS Post-Lab Submitted by Vivian M. Chan Teaching Fellow: Long Nguyen Calculations and Conclusion: In this lab, isopentyl acetate was synthesized by combining isopentyl alcohol and acetic acid. In this reaction, molecules were joined through the intermolecular elimination of water. A method of liquid extraction was used to wash the product with water, Sodium Bicarbonate and Sodium Chloride. Simple Distillation was used to retrieve a more pure product. The final crude product yield was 0.91g and the pure product yield was 0.36g.
The normality of the unknown base is calculated after the solution has reached the end point. The amount of substance being delivered is calculated in units of equivalents per litre using the formula: VaNa = VbNb Experimental In order to titrate the acid with the unknown base, a solution of the acid was prepared. 5.1722 (±10%)g of potassium hydrogen phthalate acid is obtained using a weighing boat and transferred into a volumetric flask containing 250mL of boiled distilled water. Volumetric flask was shaken several times in order to assist the powder to dissolve. Once dissolved, 24.9734 (± 0.0045)mL of acid was pipetted into an Erlenmeyer flask along with 25mL of cool (recently boiled) distilled water.
The theoretical yield of aspirin is 5.77 grams. The percent yield of aspirin is 66.3%, which was calculated by dividing the mass of aspirin (actual yield) by the theoretical yield of aspirin times 100%. A side reaction happened when acetic anhydride and water produced acetic acid. This means that when using water to rinse out the Erlenmeyer flask,
They must find the percent by mass of NaHCO3 in their baking soda product and detect if there are other salts (Ca, K, Li) present. The team with the most efficient techniques and accurate results will be crowned quality control scientists. There are two ways to determine the percent composition of NaHCO3 in the baking soda sample: Thermal Gravimetric Analysis (p.43) and Titration (p.57). Thermal gravimetric analysis is the process of introducing heat to the mixture in order to find the percent composition of it’s components. When heat is introduced, NaHCO3 will decompose into Na2CO3 (s) , CO2 (g), and H2O (l): 2 NaHCO3 (s) + heat → Na2CO3(s) + CO2 (g) + H2O(l) CO2 and H2O will be liberated from the baking soda sample and we will be left with Na2CO3 solid (assuming there are no contaminants).
Lab #3/Limiting Reagents Abstract The purpose of this laboratory experiment was to determine whether an unknown compound was sodium carbonate or sodium hydrogen carbonate by reacting a sample of it with hydrochloric acid and comparing the resulting yield of NaCl to the calculated values. The mass of an evaporating dish was taken at the start of the experiment. Then the unknown carbonate A was added in the amount of approximately one gram. The dish was weighed once more to find the definite mass of the unknown carbonate. Then, by means of a dropper bottle and stirring rod, hydrochloric acid was added until all of the unknown carbonate appeared to have reacted.
Decomposing baking soda ※ Purpose: To determine the percent yield of sodium carbonate from a decomposition reaction and to determine the percentage of sodium hydrogen carbonate in an unknown mixture. ※ Procedure: (a) Percent yield of Na2CO3 from baking soda 1. Weigh a baker, and record the mass. Add baking soda, NaHCO3, and reweigh. 2.