Silver Nitrate & Calcium Chloride
stoichiometry by: Olivia Esh
2AgNO3(aq) + CaCl2(aq) -----> Ca(NO3)2(aq) + 2AgCl(s)
For an equation to be balanced, it must have an equal amount of reactants and products. Since calcium nitrate (product side) has 2 nitrates, silver nitrate (reactant side) must have a coefficient of 2. Also, since calcium chloride (reactant side) has a subscript of 2 for Cl, silver chloride on the product side must also have a coefficient of 2.
Type of reaction, IUPAC name and molar mass for each reactant and products
silver nitrate + calcium chloride ----> calcium nitrate + silver chloride
Molar masses of each reactant and product:
AgNO3 (silver nitrate): 169.89 g/mole
CaCl2 (calcium chloride): 110.98 g/mole
AgCl (silver chloride): 143.31 g/mole
Ca(NO3)2 (calcium nitrate): 104.088 g/mole
To find the molar mass of a compound, you must look at the periodic table for each of the elements within the compound, then add the masses together to get a complete molar mass. (Remember, do not include coefficients from the balanced equation when looking for the molar mass!)
Mass of Ag: 107.86 g/mole
Mass of Cl: 35.45 g/mole
107.86 + 35.46 = 143.32
Therefore, the molar mass of AgCl is 143.32 g/mole.
Mole to Mole and Mass to Mass conversions
Given, for mole A, is students birthday (October 20th), 10.2 g of the first reactant, AgNO3.
Then use the coefficients for mole A and mole B to find the answer to the mole to mole conversion.
10.2 (g of AgNO3)* 2 mole(AgCl)/ 2 mole(AgNO3) = 10.2 g/mole
MASS TO MASS:
Use 12.1 as the given for mass A. Then use 1 for mole A, as on top mole A will always have 1, and underneath will be the molar mass of A, found on the periodic table (169.87 g/mole of AgNO3). Then use the coefficients of mole B and mole A in the mass to mass conversion. (1 CaCl2, and 2 AgNO3). Then use the molar mass of B from the periodic table over 1, which is mole B.
12.1 (g of AgNO3)* 1 mole (AgNO3)* 1 mole (CaCl2)* 110.98 (g of CaCl2)/ 169.87 (g of AgNO3)/ 2 mole (AgNO3) / 1 mole = 3.85 g
limiting and excess reactant
silver nitrate: 12.3 (g of AgNO3)* 1 mole (AgNO3)* 2 AgCl/ 169.87 (g of AgNO3)/ 2 AgNO3 = .07g
calcium chloride: 12.3 (g of CaCl2)* 1 mole (CaCl2)* 2 (AgCl)/ 110.98 (CaCl2)/ 1 mole (CaCl) = .22g
Silver nitrate is the limiting reactant, and calcium chloride is the excess.
Theoretical and Percent yield
The actual yield is the actual outcome of the equation, which is most likely larger or smaller than the theoretical yield, bringing us to the percent yield, which is the percentage the yield turned out to be either larger or smaller.
12.3 (g of AgCl)/.07 (g of AgCl)*100% = 17571% larger