Answer:
3.9 atm
Explanation:
Ideal gas law states:
PV = nRT
where P is absolute pressure,
V is volume,
n is number of moles,
R is universal gas constant,
and T is absolute temperature.
The volume of the tank is constant, so we can say:
Vā = Vā
Using ideal gas law to write in terms of P, n, R, and T:
nā R Tā / Pā = nā R Tā / Pā
nā Tā / Pā = nā Tā / Pā
Initially:
Pā = 9.8 atm
Tā = 29.0Ā°C = 302.15 K
nā = n
Afterwards:
Pā = P
Tā = 83.0Ā°C = 356.15 K
nā = n/3
Substituting:
n (302.15 K) / (9.8 atm) = (n/3) (356.15 K) / P
(302.15 K) / (9.8 atm) = (1/3) (356.15 K) / P
P = 3.85 atm
Rounding to 2 significant figures, P = 3.9 atm.
