Part A e standard Gibbs energy of formation, A G, of a substance the Gibbs energ
ID: 707020 • Letter: P
Question
Part A e standard Gibbs energy of formation, A G, of a substance the Gibbs energy change for the formation of one mole of the bstance from the component elements in their standard ates. These values are applicable at 25 C and are found in ermodynamic tables. Based on the standard Gibbs energies of formation, which of the following reactions represent a feasible way to synthesize the product? A, N2 (g) +202(g)-2NO2 (g); ?(G,-102.6 kJ mol-1 B, 2Na(s) + O2(g) Na202(s); ?,G--451.0kJ mol-1 C. N2 (g)+ O2(g) 2NO(g); D. Ca(s)+02(9) Cao( A,G-604.0 kJ mol- Drag the appropriate items to their respective bins e value of A: G for a substance gives a measure of the ermodynamic stability with respect to the component ements. Negative values for a formation reaction indicate ermodynamic stability of the product. In other words, the mpound formed does not spontaneously decompose back to the component elements. Positive values for a formation eaction indicate thermodynamic instability of the product. Thus e compound will spontaneously decompose, though the rate ay be slow. he sign of A G can be used to predict the feasibility of ynthesizing a substance from its component elements. The tandard Gibbs energy change for a reaction, A-G, is a state unction and can be calculated from the standard Gibbs energies of formation as follows: A G 173.2 kJ mol1 View Available Hint(s) Reset Help A,G" ? n,a,c (products)-? n,A: G. (reactants) Here, Ti represents the stoichiometric coefficients of the products and n, represents the stoichiometric coefficients of the reactants Feasible synthesis Not a feasible synthesisExplanation / Answer
by definition
for a reaction to be spontaneous , dGo rxn < 0
so
if dGo rxn < 0 , it would be a feasible synthesis
if dGo rxn > 0 , it would not be a feasible synthesis
so
from the given values
feasible synthesis -----> B , D
not a feasible synthesis ----> A , C