A reaction is spontaneous at all temperature if
A reaction is spontaneous at all temperature if
- A) ?G = 0
- B) ?G > 0
- C) ?S< 0 and ?H > 0
- D) ?S > 0 and ?H< 0
Correct Answer: C) ?S< 0 and ?H > 0
Explanation
This Chemistry question is asking about the spontaneity of a reaction at different temperatures. Spontaneity refers to whether or not a reaction can occur on its own without any external force or intervention.
The question provides four options to choose from. Option A states that the reaction is spontaneous if the change in Gibbs free energy, ?G, is equal to zero. Option B states that the reaction is spontaneous if ?G is greater than zero. Option C, which is the correct answer, states that the reaction is spontaneous if the change in entropy, ?S, is less than zero and the change in enthalpy, ?H, is greater than zero. Option D states that the reaction is spontaneous if ?S is greater than zero and ?H is less than zero.
It is important to note that while ?G is a good indicator of spontaneity, it is not the only factor that determines whether or not a reaction will occur spontaneously. In fact, ?G takes into account both ?S and ?H, which are the factors mentioned in option C.
Entropy, ?S, refers to the degree of disorder or randomness in a system. A negative ?S means that the system becomes more ordered, while a positive ?S means that the system becomes more disordered. Enthalpy, ?H, refers to the heat energy released or absorbed during a reaction. A positive ?H means that the reaction absorbs heat energy, while a negative ?H means that the reaction releases heat energy.
In summary, a reaction is spontaneous at all temperatures if ?S is less than zero and ?H is greater than zero, which is option C. This means that the reaction will occur on its own without any external force or intervention. It is important to understand that while ?G is a good indicator of spontaneity, it is not the only factor to consider.