Answer to Question #98559 in General Chemistry for Howard

Question

Identify the true statement(s) regarding the entropy of chemical substances.



All pure substances have a positive entropy at room temperature.


The dissolution of an ionic salt in water usually leads to an increase in entropy of the system (salt + water).


So(one mole N2O4(g)) > So(one mole NO2(g)) at 25oC.


The entropy change for the reaction N2O4(g) → 2 NO2(g) is positive.


When a metallic crystal is heated, its entropy increases due to increasing atomic vibrations.

Answer 1

a) All pure substances have a positive entropy at room temperature.

b) The dissolution of an ionic salt in water usually leads to an increase in entropy of the system (salt + water).

c) So(one mole N2O4(g)) > So(one mole NO2(g)) at 25oC.

d) The entropy change for the reaction N2O4(g) → 2 NO2(g) is positive.

e) When a metallic crystal is heated, its entropy increases due to increasing atomic vibrations.

Answer: a,b,d,e are true. C false