Calculate the free energy change for this reaction at 25 °C. Is the reaction spontaneous? (Assume that all reactants and products are in their standard states.) C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(g) ΔH°_rxn= -2217 kJ; ΔS°_rxn = 101.1 J/K

검증된 단계별 안내

Identify the given values: \( \Delta H^\circ_{\text{rxn}} = -2217 \text{ kJ} \) and \( \Delta S^\circ_{\text{rxn}} = 101.1 \text{ J/K} \).

Convert \( \Delta S^\circ_{\text{rxn}} \) from \( \text{J/K} \) to \( \text{kJ/K} \) by dividing by 1000: \( \Delta S^\circ_{\text{rxn}} = 0.1011 \text{ kJ/K} \).

Use the Gibbs free energy equation: \( \Delta G^\circ = \Delta H^\circ - T \Delta S^\circ \).

Substitute the values into the equation: \( \Delta G^\circ = -2217 \text{ kJ} - (298 \text{ K} \times 0.1011 \text{ kJ/K}) \).

Determine if the reaction is spontaneous by checking the sign of \( \Delta G^\circ \): if \( \Delta G^\circ < 0 \), the reaction is spontaneous.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Gibbs Free Energy

Gibbs Free Energy (G) is a thermodynamic potential that measures the maximum reversible work obtainable from a thermodynamic system at constant temperature and pressure. The change in Gibbs Free Energy (ΔG) for a reaction can be calculated using the equation ΔG = ΔH - TΔS, where ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy. A negative ΔG indicates that a reaction is spontaneous under the given conditions.

Standard State Conditions

Standard state conditions refer to a set of specific conditions used to measure the properties of substances, typically defined as 1 bar of pressure and a specified temperature, usually 25 °C (298 K). Under these conditions, the standard enthalpy (ΔH°) and standard entropy (ΔS°) values are determined for reactants and products. These values are essential for calculating the Gibbs Free Energy change for reactions, as they provide a reference point for the thermodynamic properties.

Spontaneity of Reactions

The spontaneity of a chemical reaction is determined by the sign of the Gibbs Free Energy change (ΔG). If ΔG is negative, the reaction is spontaneous, meaning it can occur without external energy input. Conversely, if ΔG is positive, the reaction is non-spontaneous and requires energy to proceed. Understanding the relationship between ΔG, ΔH, and ΔS helps predict whether a reaction will occur under specific conditions.

Calculate the free energy change for this reaction at 25 °C. Is the reaction spontaneous? (Assume that all reactants and products are in their standard states.) C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g) ΔH°rxn = -2217 kJ; ΔS°rxn = 101.1 J/K