Question

What will my heat gained by the calorimeter be? and total heat gained? Also do I represent heat loss of metal as negative?

Part 2: Determining the Specific Heat Capacity of an Unknown Metal Data Trial 2 Trial 1 4.62g Mass of calorimeter Mass of calorimeter + water Mass of metal 102.35 g 81.63 g 22.1 C Initial temperature of water in calorimeter Initial temperature of metal 98.8 C Final temperature of calorimeter + added metal 27.5 C Calculations Trial 2 Trial 1 97.73 g Mass of water in calorimeter (mcw) Mass of added hot metal (MHM) 81.63 g Temperature change of cool water (Qcw) 5.4 C Temperature change of hot metal (ATHM) -71.3 C Heat gained by the cool water (Qcw) 2.2x1013 J (Show calculations for one trial) Qcw=mx Specific Heat Capacity Water x Chng. C.W. Qcw= 97.73(4.184)(5.4)=2208. J (2 S.f) Heat gained by the calorimeter (Qcal) (Show calculations for one trial) Total heat gained (Qgained) Heat lost by hot metal (QHM) -2.2x10^3 J Heat capacity of metal (Cmetal) 0.38 J/gC (Show calculations for one trial) -2.2x10^3=81.639 x S x-71.3 2.2x1043/5.82x10^3=0.378

Answer 1

• Heat lost by the calorimeter in this experiment is zero, as it is assumed that the entire heat is absorbed by the water present in the calorimeter resulting in its increase in temperature.
• The total heat gained would be zero. According to the principle of conservation of heat, the heat gained is equal to the heat loss, hence the addition of heat gained by both, the metal and the water, would effectively be zero due to one being the absolute negative of the other.
  Qgained = Qgained by water + Qgained by metal = (2.2 * 103) + (- 2.2 * 103) = 0 J
• Since they have asked for heat loss i.e. they have already factored in that the heat is lost which a negative sign does, hence there is no need to include the negative sign just mention the absolute value. For further clarification, let's say you write the negative value in front of the "Heat lost by hot metal asked" since they have asked for heat lost a negative value would mean that the heat lost is negative which effectively means that heat was absorbed which negates the actual workings of the experiment.