Question

The reaction below proceeds spontaneously at 298 K.

NH3(g) +Cl2(g)mc013-1.jpgNH4Cl(s)

What is the sign of the entropy change, mc013-2.jpgS?
mc013-3.jpgS is negative because the product is less random than the reactants.
mc013-4.jpgS is negative because the reactants are less random than the product.
mc013-5.jpgS is positive because the product is less random than the reactants.
mc013-6.jpgS is positive because the reactants are less random than the product.

Answer 1

So you going from 2 moles of gaseous reactants (gases are at a high entropy state)(think of the random disorder of gas molecules) to 1 mole of solid products (solids exist at a low entropy state)(think of the high order of molecules set in place in a solid).

Answer 2

What is your prediction of how the entropy changes in the reaction?