4. The enthalpies of elements under the following conditions are us 2) Unity at 298K and 1 atm 1) Zero at 298K and 1 atm 4) Unity at 273K and 1 atm 3) Zero at 273K and 1 atm For which one of the following systems AE AE For the reaction; FECO >FeO,e CO; AH= 82.8kJ at 25C, what is (AE or AU) at 25C? 4) 85.28 kJ 7. 1) 82.8 kJ 2) 80.32 kJ 3)-2394.77 kJ 8. LIST-I LIST-II A) H > H 1) Exothermic B) PAV 2) Total heat content C) E+ PV 3) AH is positive D) H > Hp 4) Zero at constant volume The correct match is D A B C D D A B C D 1) 3 4 2 1 2) 2 3 1 4 3) 1 3 4 2 4) 1 3 4 2 9. Which of the following is an endothermic reaction ? -92KJ 2NH3(e) 1) N2) +3H2(2) 3) H2e) + Cl) 2HCI; AH =-184.6KJ 2) N22) +O2(2) +180.8KJ2 NO a 4) Cgraphite) +2H2 CHe +74.8kJ 10. The formation of water from H2e and Oe is an exothermic reaction because have a higher chemical energy that water 1) H and O, () 2) Ho and O have a lower chemical energy that water 3) He and Oza have a higher temperature than water 4) Energy considerations do not arise 11. The enthalpy of elements in their standard states are taken as zero, Hence the enthalpy of formate compound is 1) always negative 2) always positive 3) positive (or) negative 4) equal to zero 12. Identify the reaction in which the heat liberated corresponds to the heat of formation (AH) 1) C, 3) C + O CO, n + heat + 2Ha CH4) (diamond) 2) 2H + O2e) 2H, O) + heat + heat (diamond) 4) S(thmbic) + O20) + heat 13 In which of the following equations AH" reaction equals to AH, for the product ? (oS 1) 2COe +0, 2CO, 3) CHe+2CLCH,Cl(1s+2HCl 2) N+03 (2N,03 4) Xee Bi +2F XeF, 2(2) 4(g) 120 ELITE SEPI