
Respuesta :
Answer:
#Molecules XeFâ = 2.75 x 10²³ molecules XeFâ.
Explanation:
Given ⌠Excess Xe + 12.9L Fâ @298K & 2.6Atm => ? molecules XeFâ
1. Convert 12.9L 298K & 2.6Atm to STP conditions so 22.4L/mole can be used to determine moles of Fâ used.
=> V(Fâ @ STP) = 12.6L(273K/298K)(2.6Atm/1.0Atm) = 30.7L Fâ @ STP
2. Calculate moles of Fâ used
=> moles Fâ = 30.7L/22.4L/mole = 1.372 mole Fâ used
3. Calculate moles of XeFâ produced from reaction ratios âŚ
Xe + 3Fâ => XeFâ => moles of XeFâ = â (moles Fâ) = â (1.372) moles XeFâ = 0.4572 mole XeFâ
4. Calculate number molecules XeFâ by multiplying by Avogadroâs Number  (6.02 x 10²³ molecules/mole)
=> #Molecules XeFâ = 0.4572mole(6.02 x 10²³ molecules/mole)
                 = 2.75 x 10²³ molecules XeFâ.
To determine the number of molecules of XeFâ,
First, we will determine the number of moles of Fâ present in the 12.9L of Fâ
From the ideal gas equation
PV = nRT
Where P is the pressure
V is the volume
n is the amount of substance ( number of moles)
R is ideal gas constant
T is the temperature
From the question,
P = 2.6 atm
V = 12.9 L
R = 0.082057 L atm molâťÂš KâťÂš
T = 298 K
Putting these values into the equation
PV = nRT
2.6 Ă 12.9 = n Ă 0.082057 Ă 298
33.54 = n Ă 24.452986
ⴠn = 33.54 á 24.452986
n = 1.3716116 moles
The number of moles of Fâ present is 1.3716116 moles
From the given equation of reaction
Xe(g) +3Fâ(g)âXeFâ(g)
1 mole of Xe reacts with 3 moles of Fâ to produce 1 mole of XeFâ
â´ 1.3716116 moles of Fâ will give (1.3716116/3) moles of XeFâ
Hence, the number of moles of XeFâ produced = 0.457204 moles
To determine the number of molecules formed,
From the formula
Number of molecules = number of moles Ă Avogadro's number
â´ Number of molecules of XeFâ formed = 0.457204 Ă 6.02214 Ă10²³
Number of molecules of XeFâ formed = 2.7533 Ă 10²³ molecules
Number of molecules of XeFâ formed â 2.75 Ă 10²³ molecules
Hence, the number of molecules of XeFâ that are formed from 12.9 L of Fâ (at 298 K and 2.6 atm) is 2.75 Ă 10²³ molecules.
The correct option is E) 2.75 Ă 1023 molecules XeF6
Learn more about calculating number of molecules here: https://brainly.com/question/24231329