Question

15. If 5.0 mol of the substance was heated in this experiment, what is the approximate value of the molar heat capacity (Cm) for the liquid phase of this substance? A. B. C. D. E. 5.3 J.mol-1.K-1 38 J.mol-1.K-1 160 J.mol-1.K? 190 J.mol-1.K-1 270 J.mol-1-K-1

Answer 1

when the temperature is 160°c, for some heat addition temperature still semain same, so this is a phase transition a Now there are two phase transitions, lower temperature is 80°C, higher is 160°c so melting point is voc and Boiting point is (6 c. clearly between 80° to 160" AT=80°c, Heat added = (25-10) kJ = 15 kJ Cm= molar Heat capacity = 15 kJ. 5 moli 80°C = 0.038 kJimorial = 38 Jomolkn Answer- (B)