What is the percent by mass of oxygen in carbon dioxide (co2)?

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

d.) the average kinetic energy of the gas particles is greater in container b because its particles move faster.