What must be true for a spontaneous exothermic process?
If a reaction is exothermic ( H is negative) and the entropy S is positive (more disorder), the free energy change is always negative and the reaction is always spontaneous.
What must be true of a spontaneous process? Explanation: Change in free energy must always be negative for a spontaneous process. Additionally, Q must be less than K so that the reaction will proceed in the forward reaction, toward equilibrium.
A roaring bonfire is an example of a spontaneous reaction, since it is exothermic (there is a decrease in the energy of the system as energy is released to the surroundings as heat).
Which condition is always true for an exothermic reaction? Explanation: When a reaction is exothermic ("exo-" meaning out and "-thermic" having to do with heat), it means that the reaction is giving off heat into the environment. Therefore, the reactants have a net heat loss throughout the process of the reaction.
How is a reaction spontaneous? Reactions are favourable when they result in a decrease in enthalpy and an increase in entropy of the system. When both of these conditions are met, the reaction occurs naturally.
Reason: Spontaneous reactions are invariably exothermic.
The answer is D. Spontaneous reactions do not require that anything be done to them. The given statement for (D) describes a spontaneous chemical reaction.
In thermodynamics, a spontaneous process is a process which occurs without any external input to the system. A more technical definition is the time-evolution of a system in which it releases free energy and it moves to a lower, more thermodynamically stable energy state (closer to thermodynamic equilibrium).
Spontaneous processes are reactions which proceed without requiring an input of energy because the products are at a lower, more stable energy state than the reactants. Spontaneous processes often require activation energy, but do not require a prolonged input of energy.
1 Answer. An endothermic reaction can only be spontaneous under standard conditions if the increase in molar entropy is sufficient to overcome the endothermicity. If Δ G is negative the reaction is spontaneous. Usually this equation is dominated by enthalpy changes but in rare cases entropy can determine spontaneity.
Which of the following is a spontaneous endothermic process?
Melting of ice and Evaporation of water is show endothermic process.
Assertion. Decrease in free energy causes spontaneous reaction. Reason. Spontaneous reactions are invariably exothermic reactions.
Exothermic reactions absorb (take up) heat: The reactants have less potential energy than the products; D: Exothermic reactions can be used to produce energy (like heat and electricity). Both A and D are true: All of the above statements are true.
Which statement is true concerning exothermic reactions? The change in the enthalpy is equal to the amount of energy released from the reaction.
Answer and Explanation: Answer choice B is the correct response. Exothermic reactions result in the release of energy in the form of heat. The heat energy of the reactants is greater than the heat energy of the products.
A spontaneous reaction is a reaction that proceeds without external influence or the addition of energy at a given set of conditions. Reaction spontaneity is independent of reaction rate, as spontaneous reactions can occur very quickly or over many days, months, or years.
The entropy change for the system is negative.
What is true of spontaneous reactions? They are instantaneous. They are indicated by a negative change in Gibbs free energy.
Which of the following is true about spontaneous chemical reactions? The reactions are exergonic. Reactions in which there is a negative change in free energy (-ΔG) are: spontaneous and exergonic.
What is a spontaneous process? a process that proceeds on its own without any external influence or input of energy.
What causes a spontaneous process?
Spontaneous reactions release free energy as they proceed. Recall that the determining factors for spontaneity of a reaction are the enthalpy and entropy changes that occur for the system. The free energy change of a reaction is a mathematical combination of the enthalpy change and the entropy change.
According to the second law of thermodynamics, the total entropy of the universe always increases for the spontaneous processes. This law also states that for any spontaneous process, the overall change in entropy must be greater than or equal to zero.
Which of the following physical processes are exothermic for water—freezing, boiling, condensing, subliming, evaporating? Freezing and condensing are exothermic for water.
Combusting is an exothermic, chemical reaction.
ΔH is negative and ΔS is positive.
This condition describes an exothermic process that involves an increase in system entropy. In this case, ΔG will be negative regardless of the temperature. Such a process is spontaneous at all temperatures.
Combustion or burning is a high-temperature exothermic redox chemical reaction between fuel and oxidant oxygen.
Detailed Solution. An exothermic reaction is a chemical reaction which is responsible for releasing energy in the form of heat or light. 'Exo' means 'releases' and 'thermic' means 'heat'. The reaction in which there is a release of heat, with or without light is an exothermic reaction.
Therefore, respiration and burning of a candle are examples of exothermic reaction whereas evaporation of water and melting of ice are examples of endothermic reaction.
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Which of the following statements is not true for an exothermic reaction? The products have a higher heat content than the reactants.
In the case of an exothermic reaction, the reactants are at a higher energy level as compared to the products, as shown below in the energy diagram. In other words, the products are more stable than the reactants. Overall Δ H ΔH ΔH for the reaction is negative, i.e., energy is released in the form of heat.
Which of the following statements is true in an endothermic process?
Answer and Explanation: Since the enthalpy change is positive for an endothermic reaction, the enthalpy of the products must be higher than that of the reactants.
An exothermic reaction occurs when the temperature of a system increases due to the evolution of heat. This heat is released into the surroundings, resulting in an overall negative quantity for the heat of reaction (qrxn<0).
Which of the following options correctly describes an exothermic reaction? It releases more energy by forming product bonds than is needed to break reactant bonds.
In an exothermic reaction, the products of the reaction have less (chemical) energy than the reactants. In the reaction, chemical energy (stored in the bonds of chemicals) is converted to heat energy, which is released to the surroundings. The temperature of the reaction mixture and its surroundings goes up.
Summary. An exothermic reaction is a chemical reaction in which less energy is needed to break bonds in the reactants than is released when new bonds form in the products. During an exothermic reaction, energy is constantly given off, often in the form of heat. All combustion reactions are exothermic reactions.
An exothermic reaction is a chemical reaction that releases energy by light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation: reactants → products + energy.
Chemical reactions that release energy are called exothermic. In exothermic reactions, more energy is released when the bonds are formed in the products than is used to break the bonds in the reactants. Exothermic reactions are accompanied by an increase in temperature of the reaction mixture.
What is true of spontaneous reactions? They are instantaneous. They are indicated by a negative change in Gibbs free energy.
Exothermic Reactions
Heat is absorbed from the surroundings; as a result, the surroundings get cold. Heat is released by the reaction to surroundings; surroundings feel hot. The bonds broken in the reactants are stronger than the bonds formed in the products.
An exothermic reaction is a reaction in which energy is released in the form of light or heat.
Which of the following examples would be an exothermic process?
Therefore, respiration and burning of a candle are examples of exothermic reaction whereas evaporation of water and melting of ice are examples of endothermic reaction.
Firing a Firecracker – the bursting of a firecracker gives out a loud noise in addition to light and heat, being one of the best examples of an exothermic reaction. Lighting a Candle – this is a continuous reaction where the wax acts as fuel and creates a flame for a long period of time.