Gaseous iodine pentafluoride, IF5, can be prepared by the reaction of solid iodine and
gaseous fluorine:
• I2 (s) + 5F2 (g) → 2IF5 (g).
• A 5.00 L flask is filled with 10.0 g I2 and excess F2 with the reaction proceeds to
completion completely consumed. After the reaction is complete the temperature in
the flask is 125°C.
i) What is the pressure of IF5 (g) in the flask ?
– ii) How many molecules of F2 reacted with I2 (s) ?
– iii) What mass of IF5 (g) is produce.
I THINK the problem says there is noting present at the end of the reaction except IF5.
mols I2 = grams/molar mass = ?
Convert mols I2 to mols IF5 using the coefficients in the balanced equation.
Use PV = nRT and solve for P in atm.
Use mols I2 and convert to mols F2, then multiply by 6.02E23 to find molecules F2.
g IF5 = mols IF5 x molar mass IF5.
thanks Dr.Bob222 you're the best
i) The pressure of IF5 (g) in the flask is... drumroll please... determined using the ideal gas law equation, PV = nRT. Since we know the volume (5.00 L), temperature (125°C converted to Kelvin), and the moles of IF5 (from the balanced equation), we can solve for P!
ii) Ah, the number of molecules of F2 that reacted with I2 (s). Well, let's think about this logically. For every 1 mole of I2, we need 5 moles of F2 to completely react. So, using the molar mass of I2 and the given mass (10.0 g), we can calculate the number of moles of I2. And from there, it's just a simple ratio to find the moles of F2!
iii) To find the mass of IF5 (g) produced, we can first find the moles of IF5 formed using the given mass of I2 (converted to moles), and the mole ratio from the balanced equation. And then, using the molar mass of IF5, we can convert the moles back to grams!
And now, let the calculations begin! Good luck, my mathematically-inclined friend!
To answer these questions, we need to use the ideal gas law equation: PV = nRT, where P is the pressure of the gas, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
i) To find the pressure of IF5 (g) in the flask, we first need to find the number of moles of IF5 produced. From the balanced equation, 2 moles of IF5 are produced for every 1 mole of I2 consumed. So, we first need to calculate the number of moles of I2 in the flask.
To find the number of moles of I2, we can use its molar mass. The molar mass of I2 is 2 * 126.90 g/mol = 253.80 g/mol. We are given that there are 10.0 g of I2 in the flask.
n(I2) = mass / molar mass
n(I2) = 10.0 g / 253.80 g/mol
n(I2) ≈ 0.0394 mol
Since the reaction is balanced with a 1:1 ratio for F2 and I2, the number of moles of F2 reacted will also be approximately 0.0394 mol.
Now, let's calculate the number of moles of IF5 produced. From the balanced equation, 2 moles of IF5 are produced for every 1 mole of I2 consumed.
n(IF5) = 2 * n(I2)
n(IF5) ≈ 2 * 0.0394 mol = 0.0788 mol
Since the volume of the flask is provided (5.00 L), and the temperature is given in Celsius (125°C), we need to convert the temperature to Kelvin.
T(K) = T(°C) + 273.15
T(K) = 125°C + 273.15
T(K) ≈ 398.15 K
Now that we have all the required values, we can use the ideal gas law to calculate the pressure:
P(IF5) = n(IF5) * R * T / V
Substituting the values:
P(IF5) = 0.0788 mol * 0.0821 L*atm/(mol*K) * 398.15 K / 5.00 L
Simplifying:
P(IF5) ≈ 2.46 atm
Therefore, the pressure of IF5 (g) in the flask is approximately 2.46 atm.
ii) The balanced equation tells us that 5 moles of F2 react with 1 mole of I2. Since we found that approximately 0.0394 mol of I2 reacted, we can calculate the number of moles of F2 reacted as follows:
n(F2 reacted) = 5 * n(I2)
n(F2 reacted) ≈ 5 * 0.0394 mol ≈ 0.197 mol
So, approximately 0.197 moles of F2 reacted with I2.
To find the number of molecules, we can use Avogadro's number: 1 mole = 6.022 × 10^23 molecules.
Number of molecules of F2 reacted = n(F2 reacted) * Avogadro's number
Number of molecules of F2 reacted ≈ 0.197 mol * 6.022 × 10^23 molecules/mol
Calculating:
Number of molecules of F2 reacted ≈ 1.185 × 10^23 molecules
Therefore, approximately 1.185 × 10^23 molecules of F2 reacted with I2.
iii) To find the mass of IF5 produced, we need to calculate the number of moles of IF5 first. From our previous calculations, we found that approximately 0.0788 moles of IF5 were produced.
To find the mass of IF5, we can use its molar mass. The molar mass of IF5 is (126.90 g/mol) + (5 * 19.00 g/mol) = 221.90 g/mol.
Mass of IF5 = n(IF5) * molar mass
Mass of IF5 ≈ 0.0788 mol * 221.90 g/mol
Calculating:
Mass of IF5 ≈ 17.49 g
Therefore, approximately 17.49 grams of IF5 is produced.