Question

26. The internal energy can be increased by a) transferring heat from the surroundings to the ystem (b) transferring heat from the system to the surroundings c) doing work on the system A) a only B)b only C) c only D) a and c E) b and e 27. For the species in the reaction below, AHf is zero for 2Co (s) + H2 (3)+ 8PF3 () 2HCo(PF3)4) A) Co (s) B) H2 (3) C) PF3 (8) 1D) HCo(PF3)40 E) both Co(s) and H2 (g) 28. Fuel vahses of hydrocarbons increase as the H/C atomic ratio increases. Which of the following compounds has the highest fuel vałue? A) C2H6 B)C2H4 C)C2H2 D) CH4 E) CgH6 29 Of the following, which one is a state function? A) H B) 4 C) w D) heat E) none of the above 30. AH for an endothermie process is while AH for an exothermic process is A) zero, positive B) zero, negative C) positive, zero D) negative, positive positive, negative Pern B. Shew complete work for the following problenms. (20 points) 1. A 22.44 g sample of iron absorbs 180.8 J of heat, upon which the temperature of the sample increases from 21.1 C to 39.0 °C. What is the specific heat of iron? (5 points)

Answer 1