Answer:
39.1%
Step-by-step explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
S8(s) + 24F2(g) —> 8SF6(g)
Next, we shall determine the limiting reactant. This is illustrated below:
From the balanced equation above,
1 mole of S8 reacted with 24 moles of F2.
Therefore, 40 moles of S8 will react with = 40 x 24 = 960 moles of F2.
Now we can see that it will take a lesser amount of F2 than what was given to react completely with 40 moles of S8. Therefore, S8 is the limiting reactant and F2 is the excess reactant.
Next, we shall determine the theoretical yield of SF6.
Here we shall be using the limiting reactant because all of it is used up in the reaction and it will also produce the maximum yield of SF6.
The limiting reactant is S8 and the theoretical yield of SF6 is obtained as follow:
From the balanced equation above,
1 mole of S8 produced 8 moles of SF6.
Therefore, 40 moles of S8 will produce = 40 x 8 = 320 moles of SF6.
Therefore, the theoretical yield of SF6 is 320 moles
Finally, the percentage yield of SF6 can be calculated as follow:
Actual yield of SF6 = 125 moles
Theoretical yield of SF6 = 320
Percentage yield of SF6 =..?
Percentage yield = Actual yield /Theoretical yield x100
Percentage yield = 125/320 x 100
Percentage yield = 39.1%
Therefore, the percentage yield of SF6 is 39.1%