When the elements react to form compounds, negative free energy change ($\Delta G$) means
(A). spontaneous reaction
(B). free energy of the products are higher than that of reactants
(C). very high activation barrier
(D). exergonic reactions
Choose the correct answer from the options given below:
The question asks about the implications of a negative free energy change ($\Delta G$) when elements react to form compounds.
Understanding Free Energy Change ($\Delta G$)
Free energy change, often represented as $\Delta G$ (Gibbs free energy change), is a thermodynamic potential that measures the maximum or minimum electrical work that may be extracted from a thermodynamic system at constant temperature and pressure. It is a key indicator of whether a reaction will occur spontaneously.
Analyzing the Statements
- Statement (A): spontaneous reaction A negative free energy change ($\Delta G < 0$) is the fundamental criterion for a process to be spontaneous under constant temperature and pressure conditions. This means the reaction can proceed without continuous external energy input. Therefore, statement (A) is correct.
- Statement (B): free energy of the products are higher than that of reactants The change in free energy ($\Delta G$) is calculated as $\Delta G = G_{products} - G_{reactants}$. If $\Delta G$ is negative, it implies that $G_{products} < G_{reactants}$. This means the free energy of the products is lower than that of the reactants. Therefore, statement (B) is incorrect.
- Statement (C): very high activation barrier Free energy change ($\Delta G$) determines the overall spontaneity (thermodynamics) of a reaction, while the activation energy ($E_a$) determines the reaction rate (kinetics). A reaction with a negative $\Delta G$ can still have a high activation barrier, making it slow, or a low activation barrier, making it fast. A negative $\Delta G$ does not necessarily imply a high activation barrier. Therefore, statement (C) is incorrect.
- Statement (D): exergonic reactions Reactions that release free energy are called exergonic reactions. This corresponds exactly to a negative free energy change ($\Delta G < 0$). Therefore, statement (D) is correct.
Conclusion on Correct Statements
Based on the analysis, statements (A) and (D) are correct, while statements (B) and (C) are incorrect.
Identifying the Correct Option
The option that includes only the correct statements (A) and (D) is option 4.
Important Questions from Chemistry (CUET PG) Mixed
- Which of the following atmospheric gas does not dissolve in water at standard temperature and pressure conditions?
- Which of the following physical processes is responsible for the blue color of the sky?
- Arrange the following coal types in the increasing order of their heat content (KJ/kg)
(A). Peat
(B). Lignite
(C). Anthracite
(D). Bituminous
(E) Sub-bituminous
Choose the correct answer from the options given below: - In which of the following layers of atmosphere, does the temperature decrease with the increase in height from the earth's surafce?
(A). Troposphere
(B). Mesosphere
(C). Thermosphere
(D). Stratosphere
Choose the correct answer from the options given below: Choose the correct statement from the following:
(A). Water has highest density at 4°C
(B). Freezing point of water is 0°C
(C) An Ice cube does not completely dip in water, rather floats on water in a glass.
(D). Addition of common salt reduces freezing point of water.
Choose the correct answer from the options given below:
