Question

1. Which of the following will have the greatest standard molar entropy (Sº)? a. NH3(g) d. H:0(1) b. He(g) e. CaCO(s) c. C(s, graphite) 2. Indicate which of the following has the highest entropy at 298 K. a. 0.5 g of HCN b. 1 mol of HCN c. 2 kg of HCN d. 2 mol of HCN e. All of the above have the same entropy at 298 K. EVALUATING AS FOR REACTIONS (non-math recognition) 3. Indicate which one of the following reactions result in a positive A s . AgNO3(aq) + NaCl(aq) = AgCl(s) + NaNO3(aq) b. H2O(g) + CO2(g) SH.CO, (aq) H2(g) + Iz(g) = 2 HI(g) C2H2O:(g) 5 2 CO(g) + H2(g) e H:0(g) 5 H2O(1) 4. Which of the processes A-D will lead to a positive change in the entropy of the system? If all of these processes lead to a positive change in the entropy of the system, select E. Sodium chloride crystals form as saltwater evaporates. Helium gas escapes from the hole in a balloon. Water freezes in a freezer. All of these lead to a positive change in entropy of the system, as they are all spontaneous

Answer 1

For Checking motor Standard molar entropy wedo. y we check Pheese. enetropy order is liquid > Solide i ib Phase more same then we check element. element in compound then the more the a entropy en! NO2 cg) < NOz (y ) it amom cetom Same then we check mass grether the mass then the greater the entropy Xelg > Hecg).

Standard molar Entropy - The entropy at One mole of a Substance in its Standard Stute. so a greatest molar entroy (so) is NH3 (9) because it's gas and. Greather no. cat molecule 2 mole - weight molecular wight – 27gmoilt molecular weight at How a) 0.59 abHIN mol = 0.5 - = 0.018mor 27 b) Imol afhen C) 2kg at How mol= 2x10oog 279 mori - 74mol d) 2 mol at how In 9 74 mol Present.so. C have higher entropy.

I dj Cate O₂ (g) 2002(g) + H2 (9) " 1 molecuse dissociate into a molecule at gas Soi ento entropy Increase. So. Os=tve and Other option. molecule combine so. Os=-ve a) Nach (s) + H2O (1) Naon (aq) + H2O(g) entropy at system gas is evaporates. So Increase.. so cocas. Son bs=tve a b) Don't change in entropy c) When water freez then U) Convert intocs) O liquid - sold so os=-ve AU a spontanitity defand upon OG not os. 6h=0h-ToSous une