Answer to Question #78296 in General Chemistry for Chloe Lozano

Question

In which of the following equations is ΔS negative? _______

A. 4NH3 (g) + 5O2 (g) → 4NO (g) + 6H2O (g)
B. Zn (s) + HCl (aq) → ZnCl2 (aq) + H2 (g)
C. NaCl (s) + H2SO4 (l) → NaHSO4 (s) + HCl (g)
D. 2NH4NO3 (s) + Ba(OH)2(H2O)8 (s) → Ba(NO3)2 (aq) + 2NH4OH (aq) + 8H2O (l)
E. NaCl (aq) + H2O (l) + CO2 (g) → NaHCO3 (aq) + HCl (l)

Answer 1

Solution:
Changes in entropy in chemical reactions are calculated from gaseous substances. So, if molecules number of gaseous substances increases - the entropy of the system increases, with decreasing, it decreases.
Answer: E. NaCl (aq) + H2O (l) + CO2 (g) → NaHCO3 (aq) + HCl (l)