Zn(s)+2HCL(aq)------------ZnCl2(aq) + H2 (g). Is this reaction entropy change negative or positive

Question

Please help me solve

Answer 1

To solve problems like this, you should keep in mind one important concept:

Entropy of gasses > Entropy of liquids > Entropy of solids

 

In this equation, you have 1 mole of solid and 2 moles of liquid that forms 1 mole of liquid and 1 mole of gas. Gasses have much higher entropy (i.e. more disorder) than liquids and solids. If the entropy is higher on the product side, then entropy, ΔS, is positive.