A 1.252g sample containing iron dissolved and converted to Fe followed by ADDITION OF 25ML OF 0..01m K2CR2 07. THE EXCESS K2CR207 REQUIRED 6.85ML OF 0.015m SN2+. Find the percentage fe3 04 fw 213g/mol in the sample.
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I can help you with that! To find the percentage of Fe3O4 in the sample, we need to perform a series of calculations using the given information. Let's break down the steps to solve this problem:
Step 1: Calculate the number of moles of K2Cr2O7 used
First, we need to calculate the number of moles of K2Cr2O7 used. We know the volume of the K2Cr2O7 solution is 25 mL, and its concentration is given as 0.01 M (moles per liter). We can use the following formula to calculate the number of moles:
moles = concentration x volume (in liters)
Converting the volume from milliliters to liters:
volume = 25 mL = 25/1000 liters = 0.025 liters
Substituting the values into the formula:
moles of K2Cr2O7 = 0.01 M x 0.025 L
Step 2: Calculate the number of moles of Sn2+ used
Next, we need to calculate the number of moles of Sn2+ used. We know the volume of the Sn2+ solution is 6.85 mL, and its concentration is given as 0.015 M. Using the same formula as before:
volume = 6.85 mL = 6.85/1000 liters = 0.00685 liters
moles of Sn2+ = 0.015 M x 0.00685 L
Step 3: Determine the stoichiometric ratio between K2Cr2O7 and Fe3O4
To find the stoichiometric ratio between K2Cr2O7 and Fe3O4, we need to use the balanced chemical equation for the reaction between Fe3O4 and K2Cr2O7. From the equation, we can see how many moles of K2Cr2O7 are required to react with one mole of Fe3O4.
Step 4: Calculate the number of moles of K2Cr2O7 required to react with Fe3O4
Using the stoichiometric ratio found in the previous step, we can calculate the number of moles of K2Cr2O7 required to react with Fe3O4. Multiply the moles of K2Cr2O7 from Step 1 by the stoichiometric ratio.
Step 5: Determine the number of moles of Fe3O4 in the sample
Since the stoichiometric ratio tells us the number of moles of K2Cr2O7 required to react with one mole of Fe3O4, we can use this information to determine the number of moles of Fe3O4 in the sample. This value is equal to the moles of K2Cr2O7 required to react.
Step 6: Calculate the mass of Fe3O4 in the sample
To calculate the mass of Fe3O4 in the sample, we need to multiply the number of moles of Fe3O4 found in Step 5 by its molar mass. The molar mass of Fe3O4 can be determined by summing the atomic masses of its constituent elements (Fe and O) from the periodic table.
Step 7: Calculate the percentage of Fe3O4 in the sample
Finally, to find the percentage of Fe3O4 in the sample, divide the mass of Fe3O4 found in Step 6 by the mass of the sample (1.252 g) and multiply by 100.
Following these steps will allow you to find the percentage of Fe3O4 in the given sample.