Find the theoretical and actual yield of 25.0g Pb(NO3)2+15.0g2NaI=PbI2+2Na(NO2)
You made a typo in the equation; it should be
Pb(NO3)2 + 2NaI ==> PbI2 + 2NaNO3 (should be NO3 and not NO2 with NaNO3. Also, note that you don't put quantities in the equation line.
This is a limiting reagent (LR) problem. You know that because amounts are given for BOTH reactants.
mols Pb(NO3)2 = grams/molar mass = ?
mols NaI = grams/molar mass = ?
Using the coefficients in the balanced equation, convert mols Pb(NO3)2 to mols PbI2.
Do the same for converting mols NaI to mols PbI2
You will likely get different values for mls PbI2 which means one of the values is wrong. The correct value in LR problems is ALWAYS the smaller one and the reagent providing that smaller number is the LR.
Then convert mols PbI2 to grams by grams = mols x molar mass. That is the theoretical yield for PbI2. If you want theoretical yield for NaNO3 follow the procedure above to calculate that.
You can't calculate the actual yield unless you know the percent yield and that isn't given in the problem.
To find the theoretical and actual yield of a chemical reaction, we need to follow a series of steps. Let's break it down:
Step 1: Write and balance the chemical equation:
The given chemical equation is:
Pb(NO3)2 + 2NaI -> PbI2 + 2Na(NO3)
Step 2: Determine the limiting reactant:
To find the limiting reactant, we need to compare the number of moles of each reactant present using their respective molar masses.
Molar mass of Pb(NO3)2 = 331.2 g/mol
Molar mass of NaI = 149.9 g/mol
Number of moles of Pb(NO3)2 = 25.0 g / 331.2 g/mol
Number of moles of NaI = 15.0 g / 149.9 g/mol
Step 3: Calculate the stoichiometry:
According to the balanced equation, the ratio of the coefficients is 1:2:1:2. This means that for every 1 mole of Pb(NO3)2, we need 2 moles of NaI to react completely.
Step 4: Determine the theoretical yield:
The theoretical yield is the maximum amount of product that can be formed according to the balanced equation. To calculate it, we need to determine the limiting reactant.
To find the limiting reactant, compare the moles of Pb(NO3)2 and NaI calculated in Step 2. The reactant that produces the smaller number of moles is the limiting reactant.
Once you have identified the limiting reactant, use its moles to calculate the moles of the product formed. Multiply this by the molar mass of the product to get the theoretical yield.
Step 5: Find the actual yield:
The actual yield is the amount of product obtained experimentally. It is typically given in the question or measured in the laboratory.
Step 6: Calculate the percent yield:
The percent yield is calculated by dividing the actual yield by the theoretical yield, then multiplying by 100.
By following these steps, you should be able to determine the theoretical and actual yield, as well as the percent yield, in a chemical reaction.