Which of the following is an example of an exothermic reaction? silt settling out of muddy water, bubbles forming in soda, photosynthesis or fireworks

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.

50? i have no !

Moles of co₂ = 2.35/44 = 0.0534 mole.from ideal gas equation pv=nrt,  t = 18+273k = 291 kelvin.∴px5 = 0.0534x0.0821x291∴p = 0.0534x0.0821x291/5 = 0.2551 atm.now, 1 atm = 760 mm of hg  ∴ 0.02551 atm = 0.02551 x 760 = 19.38 mm of hg