Answer:
Explanation:
If we assume the balloon to be a constant pressure device and the gas filling it to be ideal.
pV = nRT
p, n and R are all constants so
V is directly proportional to T (which must be in Kelvins)
1.8/1.5 = (T + 273)/(25 + 273)
T = 84.6
T = 85°C
