Question

The objectives for this discussion forum will introduce you to the fundamental concepts of energy and how they are used in thermochemistry. Thermochemistry is the study of the relationships between heat energy and chemical reactions. You will choose from one of the following statements and then provide your assessment.

Consider an exothermic process taking place in an Erlenmeyer flask at room temperature. Choose one of the following statements, determine if it is true or false, then provide an explanation for your answer.

• The value of q for the system is negative.
• The flask is warm to the touch.
• Heat flows from the surroundings to the system.

Here are some suggestions of topics on which to elaborate upon in your explanations:

• Provide a definition of work and its relationship to enthalpy.
• The meanings of endothermic and exothermic.
• Defining a system and/or the surroundings.

Answer 1

(a)True. Explanation: In an Exothermic reaction, the enthalpy of product is less than that of reactant because product is thermodynamically more stable than reactant, as shown in figure. So the overall change in enthalpy will be negative and so the ''q''.

(b)True. Explanation: As the heat evolving from the system, it will be dissipated in surrounding and will be reflected as increase in temperature of surrounding, in this case Erlenmeyer flask.

(c) False. As explained, heat is evolving from the system and dissipated in surrounding.