Exothermic reaction normally gives out heat for completing the reaction. the burning of a candle or the condensation of water vapour to water are all exothermic reactions. The prefix "ex" at the begining refers to external or outside and normally these kind of reactions release heat at the end.During neutralization, when the acida and bases are combined, it releases heat and this kind of reaction is definitely exothermic reaction.The combustion of any kind of fuel is also exothermic reaction as it gives out heat at the end.Fossil fuel burnt in cars and engines are good examples.
Considering a reaction:
A → B
The rate equation may be described as:
r = -k[A]ⁿ
Taking the natural log,
ln(r) = -nln([A]) + ln(k)
Therefore, the only time the graph of ln[A] vs time will be a straight line is when the order of the reaction is 0, meaning the reaction is independent of reactant concentration.
There are two reasons that account for the change in concentration. One is by the physical change and second is by the chemical change. The physical change refers to the mixture of the two compounds. The concentration is the amount of that certain substance to the whole mixture. Since the mixture increases because you add them up, the concentration decreases. Second, these compounds react with each other once they interact. Hence, their amounts would be consumed in order to produce the products.
