Answer:
-71°C
Explanation:
Let's combine the Ideal Gases Law in the two situations, as the number of moles keeps on constant. Of course R, will be the same in both cases because it is a universal physic constant
P₁ . V₁ / T₁ = P₂ . V₂ / T₂
Remember that T° must be in K (T°C + 273)
-23°C + 273 = 250K
(4.62 atm . 35L) / 250K = (8.71 atm . 15L) / T₂
0.6468 L.atm/K = (8.71 atm . 15L) / T₂
T₂ = 8.71 atm . 15L / 0.6468 L.atm/K → 201.9K
T₂ = 202K - 273 = -71°C