Answer:
54.7°C is the new temperature
Step-by-step explanation:
We combine the Ideal Gases Law equation to solve this.
P . V = n. R. T
As moles the balloon does not change and R is a constant, we can think this relation between the two situations:
P₁ . V₁ / T₁ = P₂ . V₂ / T₂
T° is absolute temperature (T°C + 273)
68.7°C + 273 = 341.7K
(0.987 atm . 564L) / 341.7K = (0.852 atm . 625L) / T₂
1.63 atm.L/K = 532.5 atm.L / T₂
T₂ = 532.5 atm.L / 1.63 K/atm.L → 326.7K
T° in C = T°K - 273 → 326.7K + 273 = 54.7°C