The reaction below proceeds spontaneously at 298 K. NH3(g) Cl2(g)Right arrow. NH4Cl(s) What is the sign of the entropy change, Delta. S? Delta. S is negative because the product is less random than the reactants. Delta. S is negative because the reactants are less random than the product. Delta. S is positive because the product is less random than the reactants. Delta. S is positive because the reactants are less random than the product.