To perform this experiment, we will utilize emission spectra, titrations, and thermal gravimetric analysis, using knowledge from Experiments 10, 4, Titrations of Na2CO3 and NAHCO3 by HCl (hydrochloric acid) will be performed to determine the concentration of HCl, as well as the number of moles of HCl present within the sample of baking soda. As a result, we will be able to determine the molar concentration of HCl by determining its equivalence point (the point on the graph where the exact amount of rectant needed to perform a reaction has been added) from graphical analysis. Na2CO3(aq.) + HCl(aq.) ==> NaHCO3(aq.)
We are performing the experiment to gain our spots on the team of quality control for the Athenium Baking Soda Company. The purpose of the quality control is to determine the quality and safety of use of the baking soda. The theory behind thermal gravimetric analysis is that when a mixture is heated to a sufficiently high temperature, one component decomposes to form a gaseous compound while the other does not decompose. The mass is measured before and after the heating and stoichiometric ratios are used to determine the percent by mass. The chemical equation to be used is : 2NaHCO3(s) Na2CO3(s) + CO2(g) + H2O(g) In the second part, 1.0 M HCl will be titrated into a solution with a known amount of sodium carbonate (Na2CO3), the pH will be measured as it becomes more acidic and the equivalence point (the point at which HCL and Na2CO3 reach equilibrium) determined.
This was done by taking small amounts of the unknown acid. It was then placed into capillary tubes and inserted into the Bibby Sterilin Device. Starting with a high plateau to find a quick melting point and then proceeding to find an actual melting point. The next experiment that aided in finding more characterizations of unknown #2651145-PLF13 was equivalent weight. In order to find the equivalent weight a titration of the unknown acid had to be conducted.
The crushed coffee grounds would dissolve with the water, forming a solution of water and coffee. However, not all of the coffee beans would dissolve. The insoluble chunks of the coffee beans would remain solid and stay apart from the water. Due to the mixing of the coffee and the water, the solution would take on a brown color and have a distinct smell. 2.
Warm up Activity 1. The coffee beans would begin to disintegrate. The beans become smaller, the flavor and color from the beans will fill the water. Essentially the water will run through the coffee beans and extract its properties 2. The same thing will happen to the dry strips of seaweed.
Hypothesis: Using melting points can help determine the difference in total carbon atoms and branches between two or more compounds. Materials List: 1 Spoon 1 Paper towels 3 Small rubber bands 2 Clean sheets of paper 1 Beaker, 100 mL, glass 1 Burner-fuel 1 Burner-stand 1 Goggles-Safety 1 Magnifier, dual 1 Thermometer-in-cardboard-tube 1 Capillary tubes-3/pack 1 Tetracosane Crystals - 0.2 g in Vial 1 Tetradecanol Crystals - 0.2 g in Vial Procedures: Prior to beginning the lab exercise, read the instructions carefully. Begin by setting up a derivative melting point table to collect the data accumulated during the exercise. This lab uses heated water so be sure to follow safety procedures carefully. While conducting this laboratory experiment, be sure to use minimal amounts of each substance in order to create the habit of using only the amount necessary.
Charcoal vs. Clay Research Project, Section 571, Alejandra Navarro* and Alessandra Thompson * - Primary Author Abstract Two substances – charcoal and Bentonite clay- were tested to determine which item would be a better at adsorbing harmful PAHs (polycyclic aromatic hydrocarbons) that pollute water supplies. Through careful testing, it was proven that charcoal was a better adsorbent than the clay. Both materials adsorbed the model PAH to some extent, but charcoal would be the better choice when selecting which should be used to filter the harmful pollutants out of the water. Introduction In today’s society, water pollution caused by by-products of industrial and agricultural processes is an extremely prominent problem (Schwarzenbach, Egli, Hofstetter, et. al.).
HYPOTHESIS : What is the Dependent Variable measured: ______________________________________ What is the Independent Variable used: __________________________________________ Predict the effect of each situation/solution on the heartbeat: Make a Hypothesis for each Cold Water Hot Water 1% Ethanol Sugar Water MATERIALS • 4 Daphnia in culture liquid (per table) • Transfer pipette • a clean depression slide • Compound microscope • a small container for “used” Daphnia PROCEDURE – follow below or the modify to YOUR teacher’s instructions Keep the light for your microscope OFF as much as possible to avoid overheating your Daphnia! 1. Using a clean pipette, carefully transfer a Daphnia and ONE drop of liquid onto a slide. Keep the drop small so that the Daphnia can’t swim out of your field of view. 2.
August 23, 2009 Lab Partner-Joey Stabel The Analysis of Alum K.Schuyler Elvir Malikic Purpose Determining and understanding the characteristics of Aluminum Pre-Lab questions 1) When finding a melting point, why is it necessary to raise the temperature very slowly when approaching the melting temperature? When raising the temperature very slowly it gives the thermometer time to display the accurate temperature of the substance giving you a more accurate reading. Another reason would be the visual of things changing in a slower giving you time to examine what’s happening. 2) Washing soda is a hydrated compound whose
Ethan D. Wilhelm September 10, 2012 Chemistry 121 section 8 Friday 9-12 Sarah Gains Unknown Substance Lab Purpose: The purpose of this lab was to identify an unknown substance B by finding enough of its physical properties that we could eliminate all substances it can’t be. We use micro lab to help us find the boiling point, freezing point and mass. Then we tested the solubility of the unknown substance in water, hexane, and Alcohol. With this information we were able to find the identity of the unknown substance B. Procedure: Throughout this lab we were finding the physical properties of substance B.