A reaction which is
exothermic
(ΔH negative) and results in an increase in the entropy of the system (ΔS positive) will always be spontaneous.
Which chemical reaction is always spontaneous?
A reaction which is
exothermic (ΔH negative)
and results in an increase in the entropy of the system (ΔS positive) will always be spontaneous.
What type of reaction is spontaneous?
What is spontaneous reaction? A reaction is called spontaneous when it takes place of its own accord without any external help. It is an
exothermic reaction
and it is a spontaneous reaction . Above examples show, both exothermic and endothermic reactions could be spontaneous.
Which type of reaction is always spontaneous quizlet?
Exothermic reactions
are always spontaneous. Endothermic reactions are never spontaneous. Endothermic reactions are never spontaneous. A reaction that leads to an increase in the entropy of the system is always spontaneous.
Which type of reaction is always spontaneous an exothermic reaction?
Spontaneous and Nonspontaneous Reactions A reaction which is exothermic (ΔH negative) and results in
an increase in the entropy of the system
(ΔS positive) will always be spontaneous.
What are examples of spontaneous reactions?
A spontaneous reaction is a reaction that favors the formation of products at the conditions under which the reaction is occurring.
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).
What two factors determine whether a reaction is spontaneous?
The two factors that determine whether a reaction is spontaneous are:
Enthalpy: When the reaction gives off energy
, then the reaction is said to be spontaneous. Entropy: It is the measure of randomness in a system. As the randomness of the reaction increases, the spontaneous is the reaction.
What kind of reaction is never spontaneous?
If a reaction is
endothermic
( H positive) and the entropy change S is negative (less disorder), the free energy change is always positive and the reaction is never spontaneous.
What is needed to reverse the process of spontaneous?
A process that is spontaneous in one direction is not spontaneous in the opposite direction. The direction of a spontaneous process can depend on temperature. … To get the reverse process to occur,
the water temperature must be lowered to 0°C
. Chemical systems in equilibrium are reversible.
What is spontaneous and non spontaneous reaction?
A
spontaneous process is capable of proceeding in a given direction without needing to be driven by an outside source of energy
. … An endergonic reaction (also called a nonspontaneous reaction) is a chemical reaction in which the standard change in free energy is positive and energy is absorbed.
Which statement about spontaneous and Nonspontaneous process is correct quizlet?
Terms in this set (37) Which statement about spontaneous and nonspontaneous processes is correct?
Spontaneous processes are favored by a decrease in mc003-1. jpgH
, but nonspontaneous reactions are favored by an increase in mc003-2.
What is the enthalpy change of the reaction?
Enthalpy is the heat content of a system. The enthalpy change of a reaction is
roughly equivalent to the amount of energy lost or gained during the reaction
. A reaction is favored if the enthalpy of the system decreases over the reaction.
Is Delta H products minus reactants?
In a chemical reaction, delta H represents the sum of the heats of formation, commonly measured in kilojoules per mol (kJ/mol), of the
products minus the sum of those of the reactants
. The letter H in this form is equal to a thermodynamic quantity called enthalpy, representing the total heat content of a system.
Is Melting endothermic or exothermic?
| Phase Transition Direction of ΔH | Fusion (Melting) (solid to liquid) ΔH>0; enthalpy increases ( endothermic process ) | Vaporization (liquid to gas) ΔH>0; enthalpy increases (endothermic process) | Sublimation (solid to gas) ΔH>0; enthalpy increases (endothermic process) |
|---|
Are all spontaneous reaction exothermic?
All spontaneous processes are not exothermic
, because it is the Gibbs Free energy that determines spontaneity, not the enthalpy. … You will notice that this expression may be positive even with a negative enthalpy change (exothermic process) if the entropy change is negative and the temperature is high enough.
Do all spontaneous reactions occur quickly?
A spontaneous reaction is
always a fast reaction
. … The entropy of a system and its surroundings always increases for a spontaneous change. e. The energy of a system always increases for a spontaneous change.
