Answer:
c. 8.1 L
Step-by-step explanation:
Given that:-
Moles of oxygen gas = 0.50 mol
According to the reaction shown below as:-

3 moles of oxygen gas on reaction gives 2 moles of ozone
Also,
1 mole of oxygen gas on reaction gives 2/3 moles of ozone
So,
0.50 mole of oxygen gas on reaction gives
moles of ozone
Moles of ozone = 0.3333 mol
Pressure = 1 atm
Temperature = 25.0 °C
The conversion of T( °C) to T(K) is shown below:
T(K) = T( °C) + 273.15
So,
T = (25.0 + 273.15) K = 298.15 K
Volume = ?
Using ideal gas equation as:
PV=nRT
where,
P is the pressure
V is the volume
n is the number of moles
T is the temperature
R is Gas constant having value = 0.0821 L.atm/K.mol
Applying the equation as:
1 atm × V = 0.3333 mol × 0.0821 L.atm/K.mol × 298.15 K
⇒V = 8.1 L