Question

Why is respiration an exothermic reaction? A. a large amount of energy is released into its surroundings B. the heat content, q, of the reaction is positive C. a large amount of energy is required to activate the reaction D. there is no exchange of energy between the system and the surrounding

Answer 1

A. a large amount of energy released into its surrounding

During the respiration, glucose molecules are converted to other molecules in a series of steps. They finally end up as as carbon-dioxide and water.

The overall reaction is

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 2805 kJ

The reaction is exothermic reaction because C=O and O-H bonds in the products are so much more stable than the bonds in the reactants.

Bond energy is the average needed to break a bond.

Some bond energies are:
C-C = 347 kJ/mol
C-H = 413kJ/mol;
C-O = 358 kJ/mol;
O-H = 467 kJ/mol;
O=O = 495 kJ/mol;
C=O = 799 kJ/mol

Answer 2

Respiration is an exothermic reaction because a large amount of energy is released into it's surroundings, which is B. An exothermic reaction is a reaction that releases heat or energy into it's surroundings. During respiration, energy is released into the surrounding. Therefore it is an exothermic reaction. An endothermic reaction on the other hand takes in heat or energy from it's surrounding. Hope i helped.