During an energy exchange, a chemical system absorbs energy from its surroundings. What is the sign of ΔEsys for this process?

Name: Chemistry: A Molecular Approach
Author: Tro
ISBN: 9780137832217

Verified step by step guidance

Identify the type of process: The problem states that the chemical system absorbs energy from its surroundings, which indicates an endothermic process.

Understand the concept of energy exchange: In an endothermic process, energy is absorbed by the system, meaning the system gains energy.

Determine the sign of \( \Delta E_{\text{sys}} \): Since the system is gaining energy, the change in energy of the system (\( \Delta E_{\text{sys}} \)) is positive.

Relate to the first law of thermodynamics: The first law states that energy cannot be created or destroyed, only transferred. Here, energy is transferred into the system, increasing its internal energy.

Conclude the sign of \( \Delta E_{\text{sys}} \): Therefore, the sign of \( \Delta E_{\text{sys}} \) is positive, indicating an increase in the system's energy.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Energy Exchange

Energy exchange in a chemical system refers to the transfer of energy between the system and its surroundings. This can occur in the form of heat or work, and it is crucial to understand how energy flows to determine the changes in the system's internal energy.

Internal Energy (ΔEsys)

The internal energy of a system, denoted as ΔEsys, represents the total energy contained within the system, including kinetic and potential energy of its particles. When a system absorbs energy, its internal energy increases, leading to a positive value for ΔEsys.

Sign Convention in Thermodynamics

In thermodynamics, a sign convention is used to indicate the direction of energy transfer. If a system absorbs energy, it is considered positive, while energy released to the surroundings is negative. Thus, for a system absorbing energy, ΔEsys is positive.