Answer:
n = 1.21mol
Step-by-step explanation:
Using the formula:
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
R = gas constant (0.0821 Latmk mol)
n = number of moles
T = temperature (K)
T(K) = 25°C + 273.15
T(K) = 298.15K
Pressure in 500.0 mm Hg = 500/760
= 0.657atm
PV = nRT
0.657 × 45 = n × 0.0821 × 298.15
29.565 = 24.478n
n = 29.565/24.478
n = 1.207
n = 1.21mol