The synthesis of zinc iodide was performed using 1.8912g of zinc and 1.5965g of iodine. Determine the limiting reactant and calculate the theoretical yield of zinc iodide in grams.
Zn + I2 ==> ZnI2
mols Zn = grams/atomic mass = ?
mols I2 = grams/molar mass = ?
convert mols Zn to mols of the product using the coefficients in the balanced equation.
Do the same for converting mols I2 to mols of the product.
It is likely that these two values will not agree which means one is wrong; the correct value in limiting reagent problem is ALWAYS the smaller one and the reagent responsible for that is the limiting reagent.
Using the smaller value convert that to grams by grams = mols x molar mass = ? and this is the theoreticalyield (TY).
answer: iodine limiting and TY 103.9%
To determine the limiting reactant and calculate the theoretical yield of zinc iodide, we need to compare the amount of zinc and iodine used in the synthesis and analyze the stoichiometry of the reaction.
First, we should write a balanced chemical equation for the reaction between zinc and iodine to form zinc iodide:
Zn + I2 → ZnI2
From the equation, we see that the stoichiometric ratio between zinc and zinc iodide is 1:1, and between iodine and zinc iodide is also 1:1.
Next, we need to calculate the number of moles of zinc and iodine used in the reaction.
The molar mass of zinc (Zn) is 65.38 g/mol:
Number of moles of zinc = mass of zinc / molar mass of zinc
= 1.8912 g / 65.38 g/mol
≈ 0.0289 mol
The molar mass of iodine (I2) is 253.80 g/mol:
Number of moles of iodine = mass of iodine / molar mass of iodine
= 1.5965 g / 253.80 g/mol
≈ 0.0063 mol
Now, we can compare the moles of zinc and iodine to determine the limiting reactant.
In this case, the limiting reactant is the one that is completely consumed and determines the amount of product formed. The reactant that produces fewer moles of product will be the limiting reactant.
Looking at the balanced equation, we see that 1 mole of zinc reacts with 1 mole of iodine to produce 1 mole of zinc iodide. Therefore, the limiting reactant will be the one which has a lower number of moles, in this case, iodine.
Since the stoichiometric ratio between iodine and zinc iodide is 1:1, the number of moles of zinc iodide that can be formed will also be equal to the number of moles of iodine.
So, the theoretical yield of zinc iodide in moles is equal to 0.0063 mol.
To calculate the theoretical yield of zinc iodide in grams, we can use the molar mass of zinc iodide, which is 319.19 g/mol:
Theoretical yield of zinc iodide = number of moles of zinc iodide * molar mass of zinc iodide
= 0.0063 mol * 319.19 g/mol
≈ 2.013 g
Therefore, the theoretical yield of zinc iodide is approximately 2.013 grams.