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Enthalpy is the energy of the molecules. It cannot be measured, although CHANGE in enthalpy of reactions can be measured. It's simply heat energy. Exothermic reactions have anegative enthalpy change(which means energy of the products is lower than that of the reactants). Endothermic reactions have a positive value(energy of products is higher than that of the reactants). Entropy, on the other hand, is the degree of disorder. It's the measurement of how disordered a substance is. For example, particles in a solid are regularly arranged, so they are less disordered, and have a low value of entropy. Gases have much higher entropies. Entropy of an individual compound can be measured/calculated.
What else can I help you with?
What is the relationship between enthalpy and temperature?
Enthalpy is the amount of energy in a system and when this changes (when a reaction happens), the energy is either released (exothermic) or absorbed (endothermic) and this energy is usually released or absorbed as heat. Therefore when the enthalpy decreases, heat is released from the system making it exothermic. In contrast, when the enthalpy increases, heat is absorbed making it endothermic.
Is enthalpy a state function?
Yes it is state function
What is EEE in thermodynamics?
Energy, Entropy and Efficiency........
What is the Enthalpy of 17-4 PH stainless steel?
The enthalpy of 17-4 PH stainless steel, like other materials, is not a fixed value and can vary depending on the temperature and phase of the material. Typically, the specific heat capacity for stainless steels is around 500 J/kg·K, which can be used in conjunction with temperature change to estimate enthalpy changes. For precise enthalpy values, reference to material property databases or specific experimental data is necessary.
Internal energy and enthalpy how differ and relate to each other?
Enthalpy mathematically is the sum of the internal energy and work done in a process.internal energy is the sum of the kinetic energy,potential energy,vibrational energies etc
Is Delta S is the change in enthalpy a measure of randomness?
No, ΔS (change in entropy) and ΔH (change in enthalpy) are not measurements of randomness. Entropy is a measure of the disorder or randomness in a system, while enthalpy is a measure of the heat energy of a system. The change in entropy and enthalpy can be related in chemical reactions to determine the overall spontaneity of the process.
What characteristics of a substance is NOT affected by enthalpy and entropy?
Pressure is not affected by enthalpy and entropy.pressure
When graphing enthalpy and entropy what variables are included?
Temperature and energy are two of the variables included when graphing enthalpy and entropy. Enthalpy is made up of the energy, pressure, and volume of a system. Entropy is a way to determine the different ways energy can be arranged.
What is the definition of enthalpy and entropy?
Enthalpy is the amount of energy released or used when kept at a constant pressure. Entropy refers to the unavailable energy within a system, which is also a measure of the problems within the system.
What could make delta G become negative at a given enthalpy and entropy?
For delta G to become negative at a given enthalpy and entropy, the process must be spontaneous. This can happen when the increase in entropy is large enough to overcome the positive enthalpy, leading to a negative overall Gibbs free energy. This typically occurs at higher temperatures where entropy effects dominate.
What is the relationship between enthalpy, entropy, and free energy in a chemical reaction?
In a chemical reaction, enthalpy, entropy, and free energy are related. Enthalpy is the heat energy exchanged during a reaction, entropy is the measure of disorder or randomness, and free energy is the energy available to do work. The relationship between these three factors is described by the Gibbs free energy equation: G H - TS, where G is the change in free energy, H is the change in enthalpy, S is the change in entropy, and T is the temperature in Kelvin. This equation shows that for a reaction to be spontaneous, the change in free energy must be negative, meaning that the enthalpy change and entropy change must work together in the right direction.
How do you know if a reaction is entropy driven enthalpy driven or driven by both enthalpy and energy?
If the ∆H is positive and the ∆S is positive, then the reaction is entropy driven. If the ∆H is negative and the ∆S is negative, then the reaction is enthalpy driven. If ∆H is positive and ∆S is negative, then the reaction is driven by neither of these. If ∆H is negative and ∆S is positive, then the reaction is driven by both of these.
What could make G become negative at a given enthalpy and entropy?
Changing the temperature
How does gibbs energy relate to the changes in ethalpy and ethropy?
Gibbs energy accounts for both enthalpy (heat) and entropy (disorder) in a system. A reaction will be spontaneous if the Gibbs energy change is negative, which occurs when enthalpy is negative (exothermic) and/or entropy is positive (increased disorder). The relationship between Gibbs energy, enthalpy, and entropy is described by the equation ΔG = ΔH - TΔS, where T is temperature in Kelvin.
What is the relationship between the enthalpy h and entropy s of a reaction that is spontaneous at higher temperatures but not at lower temperatures?
The relationship between enthalpy (H) and entropy (S) is described by the Gibbs free energy equation, ΔG = ΔH - TΔS, where ΔG is the change in Gibbs free energy, ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy. For a reaction to be spontaneous at higher temperatures but not at lower temperatures, the entropy term (TΔS) must dominate over the enthalpy term (ΔH) in the Gibbs free energy equation. This suggests that the increase in entropy with temperature plays a more significant role in driving the reaction towards spontaneity than the enthalpy change.
What are the units of enthalpy?
The units for entropy are joules per kelvin (J K-1)
Predict whether the changes in enthalpy entropy and free energy will be positive or negative for the freezing of water and explain your predictions How does temperature affect the spontaneity?
The changes in enthalpy, entropy, and free energy are negative for the freezing of water since energy is released as heat during the process. At lower temperatures, the freezing of water is more spontaneous as the negative change in enthalpy dominates over the positive change in entropy, making the overall change in free energy negative and leading to a spontaneous process.
