When 1.5173g of an a organic iron compound contains Fe,C,HH and O was burned in oxygen 2.838g CO2 and 0.8122g H2O wereproduce.in a separate experiment to determine mass % of iron, 0.3355g of the compound yield 0.0758g Fe2O3.What are the empirical formula of the compound
This is a long problem but not complicated.
First, determine %Fe.
am = atomic mass
mm = molar mass
0,0758 g Fe2O3 x (2 am Fe./mm Fe2O3) = approx 0.053 and
%Fe in that 0.3355 g sample is (0.053/0.3355)*100 = approx 15.81%,
Now g Fe in the initial sample of 1.5173 = 0.1581*1.5173 = about 0.24 but you need a more accurate answer than that. Remember that is g Fe in the initial sample.
g C in the sample is mass CO2 x (am C/mmCO2) = ?
g H in the sample is mass H2O x (2*am H/mmH2O) = ?
g O in the sample is 1.5173 - gC - g H = ?
Now convert all of the grams to mols.
mols Fe = g Fe/am Fe = ?
mols C = g C/am C = ?
mols H = g H/am H = ?
mols O = g O/am O = ?
Now you want to find the ratio of the elements to one another an the formula will be FewCxHyOz and the job is find the values of w,x,y,z. The easy way to do that is to divide all of the numbers by the smallest number of the 4. I ran through the calculations and that number is for Fe and for mols Fe I obtained 0.00429. Values for w(= 1 of course), x,y,z follow. Post your work if you get stuck.
To find the empirical formula of the compound, we need to determine the number of moles for each element present.
1) Calculate the number of moles of CO2 produced:
Given:
Mass of CO2 = 2.838 g
First, let's calculate the molar mass of CO2:
C: 1 mole * 12.01 g/mol = 12.01 g/mol
O2: 2 moles * 16.00 g/mol = 32.00 g/mol
Total molar mass of CO2 = 12.01 g/mol + 32.00 g/mol = 44.01 g/mol
Now, let's calculate the number of moles of CO2 using the mass and molar mass:
Number of moles of CO2 = Mass of CO2 / Molar mass of CO2
= 2.838 g / 44.01 g/mol
≈ 0.0646 mol
2) Calculate the number of moles of H2O produced:
Given:
Mass of H2O = 0.8122 g
First, let's calculate the molar mass of H2O:
H2: 2 moles * 1.01 g/mol = 2.02 g/mol
O: 1 mole * 16.00 g/mol = 16.00 g/mol
Total molar mass of H2O = 2.02 g/mol + 16.00 g/mol = 18.02 g/mol
Now, let's calculate the number of moles of H2O using the mass and molar mass:
Number of moles of H2O = Mass of H2O / Molar mass of H2O
= 0.8122 g / 18.02 g/mol
≈ 0.045 mol
3) Calculate the number of moles of Fe2O3:
Given:
Mass of Fe2O3 = 0.0758 g
First, let's calculate the molar mass of Fe2O3:
Fe2: 2 moles * 55.85 g/mol = 111.70 g/mol
O3: 3 moles * 16.00 g/mol = 48.00 g/mol
Total molar mass of Fe2O3 = 111.70 g/mol + 48.00 g/mol = 159.70 g/mol
Now, let's calculate the number of moles of Fe2O3 using the mass and molar mass:
Number of moles of Fe2O3 = Mass of Fe2O3 / Molar mass of Fe2O3
= 0.0758 g / 159.70 g/mol
≈ 0.000475 mol
4) Determine the number of moles of each element in the compound:
Given:
Mass of compound = 1.5173 g
Using the mass percentages given for each element:
Carbon (C): 12.01 g/mol
Hydrogen (H): 1.01 g/mol
Oxygen (O): 16.00 g/mol
Iron (Fe): 55.85 g/mol
Moles of C = (Mass of compound * % mass of C) / Molar mass of C
= (1.5173 g * x / 100) / 12.01 g/mol
= 0.1267x / 12.01 mol
Moles of H = (Mass of compound * % mass of H) / Molar mass of H
= (1.5173 g * y / 100) / 1.01 g/mol
= 1.4990y / 1.01 mol
Moles of O = (Mass of compound * % mass of O) / Molar mass of O
= (1.5173 g * z / 100) / 16.00 g/mol
= 0.0948z / 16.00 mol
Moles of Fe = (Mass of Fe2O3) / (3 * Molar mass of Fe2O3)
= 0.000475 mol / (3 * 159.70 g/mol)
= 0.00000157749 mol
Equating the moles of Fe calculated from the separate experiment and the moles of Fe calculated from the empirical formula:
0.00000157749 mol = 0.1267x / 12.01 mol
Solving for x gives:
x ≈ 0.0152
Similarly, equating the moles of O calculated from the separate experiment and the moles of O calculated from the empirical formula:
0.00000157749 mol = 0.0948z / 16.00 mol
Solving for z gives:
z ≈ 0.01499
Now, we can use these values to find the empirical formula:
The empirical formula of the compound is C0.0152H0.01499Fe0.00000157749O0.01499, which can be approximated as CHFeO.
To determine the empirical formula of the organic iron compound, we need to find the ratio of the atoms present in the compound.
First, let's calculate the number of moles of CO2 and H2O produced when 1.5173g of the compound is burned in oxygen.
1. Calculate the number of moles of CO2:
The molar mass of CO2 is: 12.01 g/mol (C) + 2 * 16.00 g/mol (O) = 44.01 g/mol
The number of moles of CO2 produced is: 2.838g CO2 / 44.01 g/mol = 0.0646 mol CO2
2. Calculate the number of moles of H2O:
The molar mass of H2O is: 2 * 1.01 g/mol (H) + 16.00 g/mol (O) = 18.02 g/mol
The number of moles of H2O produced is: 0.8122g H2O / 18.02 g/mol = 0.0451 mol H2O
Next, we need to calculate the number of moles of iron (Fe) present in the 0.0758g Fe2O3 obtained from the separate experiment.
3. Calculate the number of moles of Fe2O3:
The molar mass of Fe2O3 is: 2 * 55.85 g/mol (Fe) + 3 * 16.00 g/mol (O) = 159.69 g/mol
The number of moles of Fe2O3 is: 0.0758g Fe2O3 / 159.69 g/mol = 0.000475 mol Fe2O3
Now, we need to find the ratio of moles of carbon (C), hydrogen (H), and oxygen (O) to the moles of iron (Fe).
4. Calculate the moles of carbon (C):
Since CO2 is produced by burning the compound, each mole of CO2 contains 1 mole of carbon.
Therefore, the number of moles of carbon is equal to the number of moles of CO2 produced:
Moles of C = 0.0646 mol CO2
5. Calculate the moles of hydrogen (H):
Since H2O is produced by burning the compound, each mole of H2O contains 2 moles of hydrogen.
Therefore, the number of moles of hydrogen is twice the number of moles of H2O produced:
Moles of H = 2 * 0.0451 mol H2O
6. Calculate the moles of oxygen (O):
The number of moles of oxygen can be found by subtracting the sum of moles of C, H, and Fe from the total moles of the compound burned:
Moles of O = (0.0646 mol CO2 + 2 * 0.0451 mol H2O) - 0.000475 mol Fe2O3
Finally, we can determine the empirical formula of the compound by using the molar ratios.
7. Calculate the simplest ratio of the moles of each element:
Divide the number of moles of each element by the smallest number of moles to find the simplest whole-number ratio.
For example, if Moles of C = 0.0646, Moles of H = 0.0902, Moles of O = 0.1529, and Moles of Fe = 0.000475, we would need to divide each number by 0.000475 to obtain the simplest ratio.
The empirical formula of the compound will be the whole-number ratio obtained from dividing the moles.
So, by calculating the ratios and simplifying them, you can determine the empirical formula of the compound.