a) Describe how to determine if a reaction will be thermodynamically favorable.
b) Describe what happens to the Gibbs Free Energy term when a chemical reaction is reversed.
c) Describe how coupling reactions are used to drive an unfavorable chemical reaction.
a. When a reaction thermodynamically favorable, it will be a spontaneous reaction as well as release energy. Gibbs Free energy is the amount of energy needed for a reaction to take place. If the Gibbs Free energy is negative that means that the reaction does not need an impute of energy making it thermodynamically favorable.
What to you think of this answer if it is supposed to by 2-3 sentences.
b. Gibbs Free Energy can either be negative when a chemical reaction is spontaneous or positive when a chemical reaction is nonspontaneous. When a chemical reaction is reversed, it can either go from spontaneous to nonspontaneous or the other way around. This means that the Gibbs Free Energy would either change from negative to positive or positive to negative.
What to you think of this answer if it is supposed to by 2-3 sentences.
Please help me with the last one
a) Well, to determine if a reaction will be thermodynamically favorable, you have to ask it nicely. Just kidding! The key is to look at the change in Gibbs free energy (∆G). If ∆G is negative, it means the reaction is spontaneous and will release energy. If it's positive, then it's like the reaction is saying, "Sorry, but I need more energy to happen." And if ∆G is zero, that's like the reaction being on the fence, saying, "Eh, it could go either way." So, remember to check the signs of ∆G to see if a reaction is thumbs-up or thumbs-down.
b) Ah, when a chemical reaction pulls a sneaky move and reverses, the Gibbs free energy (∆G) also has a change of heart. If it was originally positive, now it becomes negative. And if ∆G was negative, it happily transforms into positive. It's like flipping a coin and seeing the outcome go against your expectations. So, when a reaction reverses, ∆G flips like a pancake. Just remember to bring your spatula.
c) Coupling reactions, huh? They're like chemical matchmakers that bring together two reactions, one favorable and one unfavorable, to make the unfavorable one finally say, "I do." It's all about finding the right partner, you know? By linking an unfavorable reaction with a favorable one, the energy released from the favorable reaction is used as fuel to drive the unfavorable one forward. It's like having a friend who motivates you to do something you're not really keen on doing. So, coupling reactions are like chemical wingmen, making the impossible possible.
a) To determine if a reaction will be thermodynamically favorable, you can calculate the Gibbs free energy change (∆G) of the reaction. The equation for Gibbs free energy is ∆G = ∆H - T∆S, where ∆H is the change in enthalpy, T is the temperature (in Kelvin), and ∆S is the change in entropy.
If ∆G is negative, it means that the reaction is thermodynamically favorable or spontaneous, as it releases free energy. This indicates that the reaction will proceed in the forward direction without an input of energy. On the other hand, if ∆G is positive, the reaction is thermodynamically unfavorable or non-spontaneous. In such cases, the reaction will not occur spontaneously and will require an input of energy to proceed.
b) When a chemical reaction is reversed, the sign of the Gibbs free energy change (∆G) will change. If the forward reaction has a negative ∆G (thermodynamically favorable), the reverse reaction will have a positive ∆G (thermodynamically unfavorable).
This change occurs because the reverse reaction involves a change in the direction of reactants becoming products, which results in a change in the sign of the enthalpy change (∆H) and entropy change (∆S). As a result, the sign change affects the overall value of ∆G, indicating whether the reverse reaction is thermodynamically favorable or unfavorable.
c) Coupling reactions are used to drive an unfavorable chemical reaction by combining it with a favorable reaction. In this process, the energy released from the favorable reaction is used as a driving force to push the unfavorable reaction forward.
The coupling can occur by linking the two reactions together as a series of steps or by using an intermediate molecule that is common to both reactions. By doing so, the overall Gibbs free energy change (∆G) of the coupled reaction becomes negative, making it thermodynamically favorable.
In other words, the favorable reaction provides the necessary energy input to overcome the energy barrier or unfavorable conditions of the other reaction. This way, the unfavorable reaction can occur because the overall energy change of the coupled reaction is negative, allowing it to proceed spontaneously.
For 1, I think the requirement to write that much is overkill but I don't think you've said anything wrong. Make sure you clean up the typos and grammar. Perhaps you should add something about Ssysten + Ssurroundings = + the reaction will be favorable (spontaneous). Frankly I think all you need is this.
A reaction is thermodynamically favorable if delta G is negative or if Suniverse is positive (or spell it out that is the sum of Ssystem and Ssurroundings is positive) but then that isn't 2 or 3 sentences.
For #3 I really don't know what kind of coupling they are talking about or where it is in a synthesis. If you have an example and can give it to me I can probably figure it out. I suspect it is a Le Chatelier's principle thing. If the reaction is
A + B ==> C and the reactions doesn't proceed easily, one can add a reagent that will react with C such that the the combination is a ppt or a gas, that will drive the reaction to the right.
b. I don't know the sentence requirement for this one but I think all you need is
When a reaction is reversed the sign of delta G changes.