Respuesta :
Answer:
#Molecules XeF₆ = 2.75 x 10²³ molecules XeF₆.
Explanation:
Given … Excess Xe + 12.9L F₂ @298K & 2.6Atm => ? molecules XeF₆
1. Convert 12.9L 298K & 2.6Atm to STP conditions so 22.4L/mole can be used to determine moles of F₂ used.
=> V(F₂ @ STP) = 12.6L(273K/298K)(2.6Atm/1.0Atm) = 30.7L F₂ @ STP
2. Calculate moles of F₂ used
=> moles F₂ = 30.7L/22.4L/mole = 1.372 mole F₂ used
3. Calculate moles of XeF₆ produced from reaction ratios …
Xe + 3F₂ => XeF₆ => moles of XeF₆ = ⅓(moles F₂) = ⅓(1.372) moles XeF₆ = 0.4572 mole XeF₆
4. Calculate number molecules XeF₆ by multiplying by Avogadro’s Number (6.02 x 10²³ molecules/mole)
=> #Molecules XeF₆ = 0.4572mole(6.02 x 10²³ molecules/mole)
= 2.75 x 10²³ molecules XeF₆.
To determine the number of molecules of XeF₆,
First, we will determine the number of moles of F₂ present in the 12.9L of F₂
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 mol⁻¹ K⁻¹
T = 298 K
Putting these values into the equation
PV = nRT
2.6 × 12.9 = n × 0.082057 × 298
33.54 = n × 24.452986
∴ n = 33.54 ÷ 24.452986
n = 1.3716116 moles
The number of moles of F₂ present is 1.3716116 moles
From the given equation of reaction
Xe(g) +3F₂(g)→XeF₆(g)
1 mole of Xe reacts with 3 moles of F₂ to produce 1 mole of XeF₆
∴ 1.3716116 moles of F₂ will give (1.3716116/3) moles of XeF₆
Hence, the number of moles of XeF₆ produced = 0.457204 moles
To determine the number of molecules formed,
From the formula
Number of molecules = number of moles × Avogadro's number
∴ Number of molecules of XeF₆ formed = 0.457204 × 6.02214 ×10²³
Number of molecules of XeF₆ formed = 2.7533 × 10²³ molecules
Number of molecules of XeF₆ formed ≅ 2.75 × 10²³ molecules
Hence, the number of molecules of XeF₆ that are formed from 12.9 L of F₂ (at 298 K and 2.6 atm) is 2.75 × 10²³ molecules.
The correct option is E) 2.75 × 1023 molecules XeF6
Learn more about calculating number of molecules here: https://brainly.com/question/24231329