I. Introduction/ Purpose:
Stoichiometry is the study of the quantitative, or measurable, relationships that exist in chemical formulas and also chemical reactions. The calculations of a stoichiometry problem depend upon balanced chemical equations. The coefficients of the balanced equations indicate the molar ratio of the reactants and products taking part in the reaction. There are three major categories of stoichiometry problems such as mass-mass, mass-volume, and volume-volume. Convert to desired limit
Convert to moles
Along with the three major categories, after finding the quantity that you need, stoichiometry will let you find the limiting reactants and the excess reactants. The limiting reactant is the reactant that limits the amount of product formed in the chemical reaction. Also, you may find the percent yield by dividing the expected yield, the amount of product that should be produced based on your stoichiometric calculations, by the actual yield, the amount of product that is experimentally obtained from a chemical reaction.
In this lab, I have determined the reaction for mixing two reactants together; I measured out 0.005 moles of each reactant, lead (II) nitrate and potassium chromate. I dissolved, mixed, and made them react to make products; I compared the mass of the two reactants with the mass of the products. I calculated the percent yield and the percent error for this experiment and I also compared the amount I produced at the end with the amount I expected to get, using stoichiometry. II.
0.00500 moles of potassium chromate
0.00500 moles of lead (II) nitrate
Observation & Data
K2CrO4 + Pb(NO3)2 2KNO3 + PbCrO4
Mass of lead (II) nitrate used:
0.00500 mol Pb(NO3)2 × 331.2 g PbNO 1 mol Pb(NO ) = 1.7 g Pb(NO3)2
Mass of potassium chromate used:
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