Heats of Solution and Reaction Name: Cindy Hernandez Purpose: The purpose of this experiment is to decided if the chemical reactions are exothermic and endothermic. By finding the differences between each temperature. Overview: For this lab, we had three different chemicals involved NH4Cl, H2SO4, and NaOH. What we did with these chemicals was that we added water, except NaOH we added HCl, was that we combined both mixtures to determine if there was a temperature change. The reason why we're determining if their was a chemical reaction is to identify if it is exothermic or endothermic.
Before the experiment, take out the fridge water and measure out three cups and pour it into the one quart pot and measure the water temperature before placing it on the stove. Then turn the stove on to maximum heat as well as the timer. While the water is reaching to the boiling point measure and note the temperature for every minute. Next, let the stove and the pot cool down for few hours. Then take jug with room temperature water and pour out three cups into the pot.
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.
I repeated the heating and measuring process 2 more times recording the masses in the data table. I then calculated the mass of the alum by subtracting the final mass of the cup and the alum from the mass of the cup. I then calculated the mass of the water
Title: 1pt Stoichiometry Of A Precipitation Reaction 2. Procedure: 2pt (Write the procedure in your own words after you have read the lab manual) Put on goggles the weigh 1.0 of CaCl*2H2O and put it in 100ml beaker. Add 25 mil of water and stir. I will then use stoichmetry to figure out how much Na2CO3 I will need for a full reaction. I will weigh this and put it in a separate cup.
At the second titration, the experiment was exactly the same as the first titration but the H2SO4 solution was used to instead of the HCl solution. The same step as the first experiment was repeated. In the third experiment, the buret had used Ba (OH) 2 thoroughly rinsed three times. 10mL of HCl
At first we dried the crucible in the flame three times and let it come to a constant mass by measuring the weight each time. To determine percentage of water in Epsom salt, we measured about 2g of the salt into three different, dried crucibles. The crucibles were first heated gently, then intensely to drive off all the water. The final data was reported as percent hydrate with 95% confidence level. RESULTS & DISCUSSION Weights of the crucible.
Of course the saturated solutions take time this experiment is done in a two day lab setting part one should be completed during the first day and ready for use on day two. Remember because Le Châtelier’s principle if you don’t filter the solution will rise. The removal of OH- from the UN filtered solution will cause more Ca(OH)2 to be dissolved for the equilibrium to restore. The second part of this lab takes knowledge from past experiments done in this laboratory. Using the Primary method used to standardize the concentration of HCl, this will bring much lower percent error in the Ksp For this standardization sodium carbonate should be used for determining the amount of hydroxide in the solution.
After the effervescence, (15mL) of concentrated HCl was added drop wise to the solution. The mixture was then heated for 15 minutes in a boiling water bath. In two separate small beakers (20mL) of distilled water was placed in one and (20mL) of 6M HCl in the other. Both beakers were placed into an ice bath. After heating, the mixture was cooled to room temperature and filtered by vacuum filtration into a fritted funnel to yield a purple product.
Reaction : CO2+H2O → H2CO3 Technique : I will prepare a bowl that can fit 1000cc water. Then measure the initial temperature of the water using Pasco sensor first. Then, I will use insulated gloves to put one dry ice every 30 seconds and see the temperature change. I will do this continuously until 300 seconds then I stop. Variable : Control - Water, 1000cc Independent - Dry ice amount, 1-10 Dependent - Temperature Background Information: Dry ice is frozen carbon dioxide, Co2, which can make lots of fascinating experiment.