The problem tells you %Cl = 8.43%. Is this gravimetric analysis to check that number?
Convert 0.0831g AgCl to Cl. That is easiest done by 0.0831 x (atomic mass Cl/molar mass AgCl) = g Cl
Then %Cl = [(mass Cl/mass sample)]*100 =
Convert 0.0831g AgCl to Cl. That is easiest done by 0.0831 x (atomic mass Cl/molar mass AgCl) = g Cl
Then %Cl = [(mass Cl/mass sample)]*100 =
Step 1: Calculate the moles of Cl- ion in AgCl:
First, we need to determine the moles of chloride ion (Cl-) in AgCl by using its molar mass. The molar mass of AgCl is the sum of the molar masses of Ag (107.87 g/mol) and Cl (35.45 g/mol), which gives us 143.32 g/mol.
Moles of Cl- = Mass of AgCl / Molar mass of AgCl
Moles of Cl- = 0.0831 g / 143.32 g/mol
Step 2: Calculate moles of pesticide:
Now, we can find the moles of the pesticide in the sample.
Moles of pesticide = Moles of Cl- / Moles of Cl- in pesticide
Moles of pesticide = (0.0831 g / 143.32 g/mol) / (0.0843 * 8.43 g / 100 g)
Step 3: Calculate the percentage of pesticide:
Finally, we can determine the percentage of pesticide in the sample by multiplying the moles of pesticide by its molar mass, and then dividing by the total sample weight.
Percentage of pesticide = (Moles of pesticide * Molar mass of pesticide) / Sample weight * 100
Percentage of pesticide = (Moles of pesticide * 183.7 g/mol) / 0.627 g * 100
Solving the equation will give us the desired percentage of pesticide in the sample.
First, let's determine the amount of chloride ions (in moles) present in the AgCl precipitate. We can use the molar mass of AgCl to convert the given mass of AgCl precipitate (0.0831g) into moles.
The molar mass of AgCl is the sum of the atomic masses of silver (Ag) and chlorine (Cl):
Ag: 107.87 g/mol
Cl: 35.45 g/mol
Molar mass of AgCl = 107.87 g/mol + 35.45 g/mol = 143.32 g/mol
Now, we can calculate the number of moles of chloride ions (Cl-) in the AgCl precipitate:
moles of Cl- = mass of AgCl / molar mass of AgCl
= 0.0831g / 143.32 g/mol
Next, we can determine the number of moles of Cl- per mole of the pesticide. To do this, we need to know the molecular weight (MW) of the pesticide. The given MW of the pesticide is 183.7 g/mol.
Since the pesticide contains 8.43% chlorine (Cl) by mass, we can calculate the number of moles of Cl per mole of the pesticide:
moles of Cl per mole of pesticide = (8.43 g Cl / 100 g pesticide) / molar mass of Cl
= (8.43 g / 100) / 35.45 g/mol
Now, we can use the ratio of moles of Cl- in the AgCl precipitate to moles of Cl per mole of pesticide to calculate the number of moles of the pesticide in the sample:
moles of pesticide = moles of Cl- * (moles of Cl per mole of pesticide)
Finally, we can calculate the mass of the pesticide in grams using the number of moles of the pesticide and its molecular weight (MW):
mass of pesticide = moles of pesticide * MW
To determine the percentage of pesticide in the sample (with respect to the total sample mass), we divide the mass of the pesticide by the mass of the sample and multiply by 100:
percentage of pesticide in the sample = (mass of pesticide / mass of sample) * 100
Now, you can substitute the given values into the above calculations to find the percentage of pesticide in the sample.