Fireworks An exothermic reaction is one where the products have lower energy than the reactants, so the reaction yields energy. The chemical compounds present in firework fuel release a lot of energy upon oxidation. Photosynthesis is endothermic, settling of silt is not a chemical reaction, it is a physical change. Finally, the bubble formation in soda is not exothermic; otherwise, the sodas would become very hot very fast.
As we know that the volume is inversely proportional to the volume. If the pressure is rising from 1 atm to 3 atm so the volume of the ballon would decrease
P_1V_1 = P_2V_2
1.0 × 2.5L = 3 × V_2
V_2 = 0.833L
Since the air is moving from high pressure to low pressure and the two ballons are interconnected via a long pipe so the movement of the air is from bottom to top