Question

d two moles of hydrochlorhermal energy arck on the su ®, 150,0 kJ of thermal serey are released at 25.00°C and o the surroundings as work is d only P- 7. When one mole of zinc and two moles of hydrochloric acid undergo the read Zn(s) + 2 HCl(aq) → ZnCl, (aq) + He), 150,0 kJ of thermal energy are reicas 1.000 atm. The Ha gas generated does approximately 2 500 KJ of work on the surroundings as expands. Calculate AE for the reaction (assume only P-7 work is done). A. +103.31 D. +152.5 kJ B. -145.5J E. -152.51 C. - 147.51 8. Which statement below regarding heating curves is FALSE? A. A heating curve tracks the temperature of a system as it is heated at a constant rate. B. Different substances will have different heating curves. C. A heating curve will reflect the amount of material present. D. When a substance undergoes a phase change, there is no energy change because the temperature is constant. E. If a cooling curve were to be made, the amounts of energy would be equal to those in a heating curve but opposite in sign. 9. You hold a 50 g sphere of copper (c=0.4 J/g. C)] in one hand and a 25 g sphere of aluminum [p = 0.9 J/g °C) in the other hand. If both absorb energy at the same rate, which will come to your body temperature first and why? A. copper, because the mass is larger B. aluminum, because the specific heat is larger C. aluminum, because the mass is smaller D. copper, because the heat capacity is smaller E. Both reach body temperature at the same time because they absorb energy at the same rate. 10. Given that molar enthalpy of combustion of acetylene (C2H2, 26.04 g/mol) is -1299 kJ/mol at 25°C and 1 atm, which statement below is FALSE? CH (8) + (8) ► 200,(@) + H20(1) A. The enthalpy of the reactants is lower than that of the products. B. The amount of heat released is proportional to the amounts of reactants. C. When 104 g CH2 combusts, about 5200 kJ of heat is released. D. The enthalpy of combustion per gram acetylene is-49.9 kJ/g. E. To form 2 mol CH2 and 5 mol O2 from 4 mol CO2 and 2 mol H20, 2598 kJ of energy is required.

Answer 1

using using AE - First lau qtw q - 15o kt o – 2.500 125 DES – 150 + (-2.5) - - 152.5kg - ③ wrony, because during phase change AETO - 04 olgun copper - 0.gglyc Al q=50CAT I = 25LAT sox0.4 - 225 At ) q, 2011 ③ ne has high ep. To moles of call in lood - 104 - 4 Aus A 26 false total energy - 4x (1299) -- ~5196 -1299 26 -49.9K 2.590 As on,20 so enthapply of product is lower the 6 +12gs x 2 = 2598 reatat