0.281g of Fe(NH4)2(SO4)2*6H2O is dissolved in a total volume of 500.0 mL of water, calculate the resulting Fe concentration in ppm.
molar mass of Fe(NH4)2(SO4)2*6H2O = 392.14088g/mol
molar mass of Fe = 55.845g/mol
0.281g * (1mol/392.14088g) = 7.165X10^-4 mol
7.165X10^-4 mol * (1mol Fe/ 1mol Fe(NH4)2(SO4)2*6H2O) = 7.165X10^-4 mol Fe
7.165X10^-4 mol (55.845g Fe/ 1 mol Fe) = 0.040017g Fe
0.040017g Fe / 500.0mL = 8.003X10^-5g/mL
(8.003X10^-5g/mL)(1000mL/L) = 0.08003g/L
(0.08003g/L)(1000mg/g) = 80.0mg/L
80.0mg/L = 80.0 ppm since 1mg/L = 1ppm
That looks good to me. Good work.
The resulting Fe concentration in ppm is 80.0 ppm.
To calculate the resulting Fe concentration in ppm, we need to follow these steps:
1. Start with the given mass of Fe(NH4)2(SO4)2*6H2O, which is 0.281g.
2. Calculate the number of moles of Fe(NH4)2(SO4)2*6H2O by dividing the mass by the molar mass, which is 392.14088g/mol. So, 0.281g / 392.14088g/mol = 7.165×10^-4 mol.
3. Convert the number of moles of Fe(NH4)2(SO4)2*6H2O to moles of Fe by multiplying by the ratio of moles of Fe to moles of Fe(NH4)2(SO4)2*6H2O. The ratio can be found by looking at the chemical formula, which shows that there is one mole of Fe for every one mole of Fe(NH4)2(SO4)2*6H2O. So, 7.165×10^-4 mol × (1 mol Fe / 1 mol Fe(NH4)2(SO4)2*6H2O) = 7.165×10^-4 mol Fe.
4. Calculate the mass of Fe by multiplying the moles of Fe by the molar mass of Fe, which is 55.845g/mol. So, 7.165×10^-4 mol × (55.845g Fe / 1 mol Fe) = 0.040017g Fe.
5. Divide the mass of Fe by the total volume of water in liters (converted from milliliters) to find the concentration in g/mL. In this case, the total volume is 500.0 mL, which is equal to 0.5 L. So, 0.040017g Fe / 0.5L = 8.003×10^-5g/mL.
6. Convert the concentration from g/mL to g/L by multiplying by 1000 mL/L. So, 8.003×10^-5g/mL × 1000 mL/L = 0.08003g/L.
7. Convert the concentration from g/L to mg/L by multiplying by 1000 mg/g. So, 0.08003g/L × 1000 mg/g = 80.0mg/L.
8. Finally, since 1mg/L is equal to 1 ppm, the resulting Fe concentration is 80.0 ppm.
Therefore, the resulting Fe concentration in ppm is 80.0 ppm.