Question

Why is it necessary to specify the temperature when making a table listing \(\Delta G\) values?

Short answer

Temperature affects \(\bm{\text{ΔG}}\) values, influencing the spontaneity of reactions and ensuring data consistency.

Step-by-step solution

Understand \(\bm{\text{ΔG}}\) - Gibbs Free Energy

Gibbs Free Energy, denoted as \(\bm{\text{ΔG}}\), measures the amount of reversible work a system can perform at constant temperature and pressure. It indicates the spontaneity of a reaction.

Factor In Temperature Dependence

The value of \(\bm{\text{ΔG}}\) depends on temperature because the equation \(\bm{\text{ΔG} = \text{ΔH} - T\text{ΔS}}\) includes temperature (T) directly. A change in temperature alters \(\bm{\text{ΔG}}\).

Impact on Reaction Spontaneity

At different temperatures, \(\bm{\text{ΔG}}\) values can change, influencing whether a reaction is spontaneous or non-spontaneous. Accurate \(\bm{\text{ΔG}}\) values must be associated with specific temperatures.

Consistency in Data Presentation

When compiling a table with \(\bm{\text{ΔG}}\) values, specifying the temperature ensures consistency and comparability among different entries.

Key concepts

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Gibbs Free Energy, represented as \(\text{ΔG}\), is a thermodynamic property that helps us understand how much work a system can do when temperature and pressure are constant. To correctly analyze and compare \(\text{ΔG}\) values, we must consider the temperature at which these values are determined.

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Gibbs Free Energy (\text{ΔG}) depends on temperature because the equation \(\text{ΔG} = \text{ΔH} - T\text{ΔS}\) includes temperature (\text{T}) directly. This equation states that \(\text{ΔG}\) is the difference between the change in enthalpy (\text{ΔH}) and the temperature times the change in entropy (\text{ΔS}). As temperature changes, \(\text{ΔG}\) also changes because \(\text{ΔS}\) is typically not zero.

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Whether a reaction occurs spontaneously depends on the value of \(\text{ΔG}\). At a specific temperature, if \(\text{ΔG}<0\), the reaction is spontaneous; if \(\text{ΔG}>0\), the reaction is non-spontaneous. Spontaneity can change with temperature, thus it is necessary to state the temperature when discussing \(\text{ΔG}\) values. This understanding is crucial for predicting reaction behavior under different conditions.

headline of the respective core concept

Consistency in data presentation is imperative when compiling tables of \(\text{ΔG}\) values. By specifying the temperature, entries become comparable. This consistency allows us to accurately predict reactions, analyze thermodynamic data from various sources, and perform precise thermodynamic calculations. Without temperature specifications, the interpretation of \(\text{ΔG}\) values would be inconsistent and potentially misleading.