Step 1
It is assumed that the gas is ideal:
p x V = n x R x T (1)
p = pressure = 0.98 atm
T = 125 °C => in Kelvin => T = 125 °C + 273 = 398 K
V = volume = unknown
R = gas constant = 0.082 atm L/mol K (according to the units of the variables)
n = number of moles = 1 mole
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Step 2
V is cleared from (1):
V = n x R x T/p = (1 mole x 0.082 atm L/mol K x 398 K)/0.98 atm = 33.3 L
Answer: V = 33.3 L