The air temperature outside a flask in which a reaction is occurring changes from 20°c to 29°c over a period of 15 seconds. what kind of reaction do you know is occurring inside the flask?
a. exothermic b. combustion c. endothermic d. spontaneous

Option A, Exothermic

Explanation:

In an exothermic reaction, energy is released after the completion of chemical reaction in the form of either light or heat. Here the temperature of flask has increased from 20°C to 29°C. This means that has been a rise in temperature by 6°C. This extra heat is coming from the chemical reactions taking place within the flask. In an endothermic reaction, heat is taken in to initiate and complete the reaction. In combustion, the temperature must be extremely high and in spontaneous reaction there is sudden change in physical and chemical conditions thereby attaining a thermodynamically stable condition.

Hence, option A is correct

answer; i believe that the correct answer is (lung);