(1) The rusting of iron is an exothermic reaction and this process is used in hand warmers which are utilized in cold regions.(2) For these exothermic processes, the solubility decreases with an increase in temperature.(3) When fireworks are ignited, the chemical compounds react with each other in an exothermic reaction - releasing energy.(4) Sodium hydroxide dissolved into water is an exothermic process, ammonium nitrate dissolved in water is an endothermic process.(5) Inside the mold, the liquid undergoes an exothermic chemical reaction, which forms the polyurethane polymer in the mold.(6) Little heat is needed in the roasting of sulfide ores because the oxidation of the sulfide ion to sulfur dioxide is exothermic .(7) This is because fluorine generally reacts exothermically to form products with stable C-F bonds.
