When vinegar (CH3COOH) and baking soda (NaHCO3) are combined, the mixture spontaneously undergoes an endothermic reaction while releasing CO2 gas. Would the test tube feel hot or cold? Do you think this reaction would have a + or − value for ΔG? Explain your reasoning.
To determine:
If the test tube containing the given reaction mixture of vinegar and baking soda is hot or cold.
Introduction:
Thermodynamics is the branch of chemistry which studies the difference of heat and energies of product and reactant in the chemical reaction. Therefore, the sign of free energy change and heat change for a given chemical reaction is predicted by using the concept of thermodynamics.
Explanation of Solution
Endothermic reactions are the reactions in which heat is absorbed. In endothermic reactions, the flow of heat is inside the reaction mixture that results in a positive value of enthalpy change.
Exothermic reactions are the reactions which involve the release of heat. In exothermic reactions, the flow of heat is outside the reaction mixture that results in the negative value of enthalpy change.
A spontaneous process is a process which does not require any external effort for its initiation and a non-spontaneous process is a process which requires heat for its initiation.
As per the given facts, the temperature of the given test tube containing the reaction mixture depends upon the enthalpy change of the reaction. If enthalpy change of the reaction is positive, the test tube will be cold after the completion of the reaction and if the enthalpy change is negative, the test tube will be hot after the completion of the reaction.
Since the given reaction is given to be spontaneous and endothermic in nature; therefore, heat flows inside the reaction mixture and test tube containing the reaction mixture will be cold after the completion of the reaction.
To determine:
The sign of
Introduction:
The free energy change
Explanation of Solution
The free energy change
Since the stated reaction is given to be spontaneous in nature; therefore, the free energy change of the reaction is negative.
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Chapter 5 Solutions
General, Organic, and Biological Chemistry; Modified Mastering Chemistry with Pearson eText -- ValuePack Access Card (3rd Edition)