Question

17. When 13.8 ml of 0.870 M lead(II) nitrate reacts with 90.0 ml of 0.777 Msodium chloride, 0.279 kJ of heat is released at constant pressure. What is Alt for this reaction? Pb(NO ) ) + 2NaCl(a) - PC(s) + 2NaNO3(aq) a 23.3 kJ b. 4 1.84 kJ d. 3.411 e. &J 18. A 1.67-g sample of solid silver reacted in excess chlorine gas to give a 2.21-g sample of pure solid AgCl. The heat given off in this reaction was 1.96 M constant pressure. Given this information, what is the enthalpy of formation of AgCl)? a. 127 /mol .-63.5 L/mol c. 127 kJ/mol d. 196 mol c. 1.96 kmol -3915 19. What is the standard enthalpy of formation of liquid butyraldehyde, CH CH.CH.CHOKI? CHUCHỊCH CHOI) + O2 = 4H CHI) + 4COMg, AH = -347 ,8 ky Substance Arck/mol) COS) HO) 285.8 2.-245 4 /mol b. +245.4 kmol -1795 /mol d.-3151.1 kmol e. +3151. /mol O. ) 20. What is the standard enthalpy change for the following reaction? 3CH ) + 40.) 3CO () + 6H2O ) Substance Alk/mol) CHg) -74.87 +142.7 COAR) -3915 H:O ) -241.8 a.-2285.1 b. -2977.5 kJ c. +2977.5 W d. +2285.1 e-3426,5 J

Answer 1

11) moles of Pb(NO3), = 13.8 X0-870/1000 0.012 S moles of Nad , 900X0.777/1000 = 0.06993 Pb(NO₃)₂ + 2 Nad obel, + 2NaNO3 0.012 0.07 here limiting limiting reaa eut is pb CNO3 DHE - @ſn = 0.2797012 = 23.3 KT TAH' = 23.3kg mole of Ag = 1-67/109.89 = 0.0155 Q=1.96KT = 70% 127 DH = -127 *7 /mol CH3CH2CH2CHO +502 + 4H207 4002 o Hyeon = (4x-285-8 +4x -393-5) - (OHjerty(te) - 241-8 - - 21H -- 3+ CH3C4, cá, CHO C+4H = -24 5.4 kg (mal - 24. 4 C+gC4, C4, G30 20) 60- 2977.5kg