Heat Capacity Learning Goal: To understand the concepts of heat capacity, specific heat, andmolar heat capacity. Heat capacity, C, is the amount of energy required toraise the temperature of a substance by exactly 1 degree Celsius.The energy needed to warm an object increases as the mass of thatobject increases. We see this in our everyday life. For example, weknow that it takes much more energy to heat a large tank of waterthan a small cup. Because of this dependence on mass,experimentally determined heat capacities are always reported interms of the amount of the substance that is heated. One method isto report how much energy it takes to raise the temperature ofone mole of a substance by exactly 1 degree Celsius. Thisvalue is the molar heat capacity, which has the symbolCp.The molar heat capacity is given in the unitsJ/(mol⋅∘C). A second method is to report how much energy it takesto raise the temperature of one gram of a substance byexactly 1 degree Celsius. This value is the specific heat,which has been given the symbol Cs. The units for specificheat are J/(g⋅∘C).The heat capacity of a substance is therefore related to theenergy q needed to raise its temperature by an amountΔT. That is, q=nCpΔT,where n denotes the number of moles of the substance, orq=mCsΔT, where mdenotes the number of grams of the substance. | Part A It takes 51.0 J to raise the temperature of an 11.1 g piece ofunknown metal from 13.0∘C to 24.3 ∘C. What is the specific heat forthe metal? Express your answer with the appropriate units. SubmitHintsMyAnswersGive UpReviewPart Parts B and C The next two questions pertain to silver. They have nothing todo with unknown metal described in Part A. Part B The molar heat capacity of silver is 25.35 J/mol⋅∘C. How muchenergy would it take to raise the temperature of 11.1 g of silverby 15.8 ∘C? Express your answer with the appropriate units. SubmitHintsMyAnswersGive UpReviewPart Part C What is the specific heat of silver? Express your answer with the appropriate units. SubmitHintsMyAnswersGive UpReviewPart |
