Explanation:
Entropy refers to the degree of disorderliness of system. Basically it refers to how random a system is.
Gong through the options.
A. The phase change is from solid to liquid. Liquid has a greater degree of disorderliness compared to solid hence entropy is increasing.
B. The phase change is from solid to gas. Gas particles has a greater degree of disorderliness compared to solid hence entropy is increasing.
C. The phase change is from aqueous to liquid. Aqueous solutions has a greater degree of disorderliness compared to liquid hence entropy is decreasing.
D. The reactant side has; solid + gas. In the product side, there is only gas. The product side has a greater degree of disorderliness hence the entropy is increasing.
E. The entropy of the product is greater than the entropy of the reactants hence entropy is increasing.
F. The phase change is from aqueous to solid. Aqueous solutions has a greater degree of disorderliness compared to solid hence entropy is decreasing.
Answer: as copper has lower electrode potential value than hydrogen, it could be reduced by hydrogen.
Explanation: hydrogen has zero reduction potential while Cu has +0.34V and Al has -1.66 V .
SO in electrochemical series who has most negative or less reduction potential value tends to be a good reducing agent than the other.
Hope it helps...
