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Solve this: germochemistn_ : 50 min Chemistry Daily Practice Problems DPP.NO. 1 When 2 molesofC2H6 are completely burnt 3120 kJ ofheatisliberated. Calculate the heat of formation, AHf0forC2H6. GivenAHf0 286kJrespectively, 2. ,W1he standard heats of formation of CH4 (g) , and H20 are —76.2, —398.8 , —241.6 kJ mol-l. Calculate amount of heat evolved by burning 1 ni3 ofmethane measured under normal (STP) conditions. Theheatofreaction HCI (g) at 270Cis —22.1 kcal .Calculatethe heat ofreaction at 770 C. The molar heat capacities at constant pressure at 270C for hydrogen , chlorine & HCI are 6.82, 7.70 & 6.80 cal mol -1 respectively. Calculate standard heats offormation of carbon—di—sulphide (l) . Given the standard heat of pombustion Ofcarbon (s) , sulphur (s) & (l) are : — 393.3, — 293.72 and — 1108.76 kJ mol respectively. A cylinder ofgas supplied by a company contains 14 kg ofbutane . The heat OfcombustiOn of butane is 2658 kJ/mol . A normal family requires 20 MJ of energy per day of cooking. Ifthe for lasts cylinder 26 days, what percentage ofgas is wasted due to inemcient combustion. The enthalpy change for the reaction C3H8 + H2(g) —5 C2H6(g) + CH4(g) at 250 C' is — 55.7 kJ/mol. Calculate the heat of combustion of C2H6(g). The heats of combustion of H2, CH4 & Cyaphite are — & — 393.5 kJ/mole respectively. Heat of combustion of propane is —2220 kJ mol-l. At 300K, the standard enthalpies of formation of C6H5COOH(s), C02(g) & H20(l) are ; —408, —393 & —286 KJ mol-l respectively. Calculate the heat of combustion of benzoic acid at:(i) constant pressure (ii) constant volume. O. The heat liberated on complete combustion of 7.8 g of benzene is 327 kJ . This heat has been measuredatconstant volume & at 270 C. Calculatethe heat of combustion ofbenzene at constant pressure. When 12 ofC reacted with oxygen to form CO(g) and C02(g) at 250C and constant pressure, 313.8 KJ of heat was released and no carbon remained. Calculate the mass of oxygen which reacted. [CO(g)] =-110.5 KJ/m01e; [COO] = -393.5 KJ/m01e. A gas mixture of 3.67 litre of ethylene and methane on complete combustion at 250C produces 6.11 litre ofCOT ofcombustion ofethylene and methane are -1423 and -891 KJ/moIe at 250C.