Student: Rene CantuDate: 10/30/14
Partner: Brandon MendezSection: 110
Group #: 10
Experiment 7
Investigating Stoichiometry with Sodium Salt of Carbonic Acid
Introduction
The Problem that was introduced in this lab is that we as a group were using stoichiometry to react different reactants of either sodium bicarbonate or sodium carbonate and hydrochloric acid to produce sodium chloride and carbon dioxide. The problem is that we don’t know what we are reacting at each time: sodium bicarbonate or sodium carbonate with hydrochloric acid at each time, and we will use the chemical reaction to then measure the amount of the physical product that is left over and if it is closer to the true values of whichever sodium bicarbonate or sodium carbonate, then we will discover that this is the compound that the unknown was.
Stoichiometry is a branch of chemistry that deals with relative quantities of reactants and products in chemical reactions. Stoichiometry can be used to find quantities such as the amount of products that can be produced with given reactants and percent yield. This is the process we will use to discover the true values of our given unknowns with each trial and we will use our percent yields to test how close we were to finding the true value of the compound after we have discovered which compound it is.
The hypothesis and expected results is that we will discover which compound is which in the end and that the percent yields will lie somewhere around 70 and 80 percent after calculating the actual yield over the theoretical yield to find the total percent yield of each compound.
Experimental Procedure
This experiment was using of stoichiometry to react different compounds together to get a final result and measure out the final result after boiling out the product to get the physical product remaining. That physical residue left in the reaction will be the mass of the unknown and will determine if the unknown is sodium bicarbonate or sodium carbonate depending on the weight of each product. After that is done for each individual unknown in both balanced equations, then the percent yields of each product will be calculated to see how close we were to the actual values that were given for each unknown after we discovered which is which. We poured the unknown physical reactant in a flask with hydrochloric acid and mixed the two to produce water and CO2 and either sodium chloride or 2 sodium chloride, depending on what the unknown was with two different true values to discover it the unknowns were NaHCO3 or Na2CO3.
Results
Unknown #1 Results (Weight in g) Unknown Conclusion
Experimental (Theoretical) (m) 0.09240 The unknown was concluded to be NaHCO3
True Value (m) 0.10521 % Yield 87.82000 Unknown #2 Results (Weight in g) Unknown Conclusion
Experimental (Theoretical) (m) 0.15170 The unkown was concluded to be Na2CO3
True Value (m) 0.12490 % Yield 0.75500 From these tables, the weights of the dry products that were taken after boiling the products to get the physical product alone are included that were used to finalize what the unknowns were depending on the amount of grams left over after each procedure was followed with each individual unknown. The percent yields and conclusions of