C125 EXAM-QUESTIONS WITH CORRECT ANSWERS

C125 EXAM-QUESTIONS WITH CORRECT ANSWERS 3.Write a balanced chemical equation noting all species and states of matter 4.Break up any aqueous compound into its ions to write the total ionic equation (including states of matter) 5.Cancel out any spectator ions 6.Write the remaining species as the net ionic equation Endothermic - Answer- - Absorbs heat from the surroundings - Becomes colder; requiring a gain of energy Exothermic - Answer- - Releases energy to it surroundings - Becomes warmer; requiring a loss of energy Mode Final Temp. - Answer- - Peak temp reached by the system before energy is then lost by the system - Temp change in the system = mode final temp. - initial temp. Heat Capacity (C) - Answer- - # of heat units needed to raise the temperature of the substance in a specific calorimeter by one degree kelvin - C [=] J/K - Does not take account the mass of the substance - C = q/ Delta T Specific Heat (Csh) - Answer- - Amount of heat required to raise the temperature of one gram of the substance by one degree Kelvin - Csh [=] J/g x K - Takes into account the mass of the substance - Specific Heat of Water: 4.184 J/g x K - Csh = q / m x Delta T Heat of Reaction (Delta H rxn) - Answer- - Difference between the enthalpies of the products & the enthalpies of the reactants - AKA. enthalpy of reaction - Negative sign; heat lost - Positive sign; heat gain Constant Pressure Calorimeter - Answer- - Used to determine heat changes for non-combustion reactions - The heat change for the process = enthalpy change