Stoichiometry Lab
I. Statement of Purpose
The purpose of this lab was to determine the mass and mole relationship among the products and reactants for the reaction of copper with silver nitrate. The coefficients of the balanced chemical equation were then verified and the percent yield of silver metal was calculated.
II. Background
This lab related with a branch of chemistry called stoichiometry, which deals with the numerical relationships and mathematical proportions of reactants and products in a chemical reaction. The reactants and products in a reaction are related to each other on a mole basis. The coefficients of the equation are the relative numbers of moles of each reactant and product involved, which represents the mole ratios. Percent yield can be derived from dividing the theoretical yield of a product from the actual yield, and multiplying that by 100. This reveals the accuracy of the experiment- how close the actual amount of product was made, compared to the amount that should have been made.
III. Summary of Procedure
Silver nitrate crystals were placed in a beaker, and the beaker was weighed. Distilled water then went into the beaker to dissolve the crystals. Coiled copper wire was weighed and hooked on a wooden splint, which was then suspended in the solution. Nitric acid was added, the observations recorded, and then the beaker was left undisturbed overnight. The copper wire was lifted out of the beaker and distilled water was used to rinse off the silver crystals. The copper wire was dried using acetone rinse, and the final mass was recorded. The silver was rinsed and decanted several times, the beaker containing the silver was heated dry on a hot plate (isolating the silver), cooled, and then weighed.
IV. Observations
• When copper was added to the silver nitrate, along with 3M nitric acid, the copper wire turned black, then whitish.
• The wire continued to become whiter as it became fuzzy
• Crystals formed on the wire, making...