Pyrites, FeS2, are a pollution-causing impurity in some coals. Upon combustion, the following rxn takes place:
2FeS2 + 5O2 à 4SO2 + 2FeO
What volume of 6.0 M NaOH would be required to react with the SO2 produced from 1000 kg of coal containing 0.050% by mass of pyrite impurity?
2NaOH + SO2 à Na2SO3 + H2O
I don't know where to start...what do I do with that .05%?
1000 kg coal = 1,000,000 g coal and if that contains 0.050% FeS2, then
1,000,000 x 0.0005 = ? g FeS2 to start. Go through the stoichiometry to find how much SO2 is produced, then do the stoichiometry to find NaOH required.
200
To solve this problem, we need to calculate the number of moles of pyrite impurity and then find the number of moles of SO2 produced from it. Once we have the number of moles of SO2, we can use stoichiometry to determine the number of moles of NaOH required. Finally, we can convert the number of moles of NaOH into its volume using the given concentration.
Let's break down the problem step by step:
1. Calculate the mass of pyrite impurity in the coal:
Mass of coal = 1000 kg
Percentage of pyrite impurity = 0.050%
Mass of pyrite impurity = (0.050/100) * 1000 kg
2. Convert the mass of pyrite impurity into moles:
Molar mass of FeS2 = atomic mass of Fe + 2 * atomic mass of S
Molar mass of Fe = atomic mass of Fe = 55.845 g/mol
Molar mass of S = atomic mass of S = 32.06 g/mol
Molar mass of FeS2 = 55.845 + 2 * 32.06 g/mol
Now, calculate the number of moles of pyrite impurity:
Moles of pyrite impurity = (Mass of pyrite impurity) / (Molar mass of FeS2)
3. Use the stoichiometry of the reaction to determine the number of moles of SO2 produced:
From the balanced equation, we can see that:
2 moles of FeS2 produce 4 moles of SO2
Moles of SO2 = (Moles of pyrite impurity) * (4 moles of SO2) / (2 moles of FeS2)
4. Determine the number of moles of NaOH required using stoichiometry:
From the balanced equation, we can see that:
2 moles of NaOH react with 1 mole of SO2
Moles of NaOH = (Moles of SO2) * (2 moles of NaOH) / (1 mole of SO2)
5. Convert the number of moles of NaOH into volume using the given concentration:
Concentration of NaOH = 6.0 M (6.0 moles per liter)
Volume of NaOH = (Moles of NaOH) / (Concentration of NaOH)
By following these steps, you should be able to calculate the volume of 6.0 M NaOH required to react with the SO2 produced from 1000 kg of coal containing 0.050% by mass of pyrite impurity.