Final exam -CHEM 111 Questions and All Correct Answers Updated.

What happens to delta H when you reverse the equation? - Answer The sign changes but not the magnitude of delta H What must happen in an equation when multiplying by factor (n)? - Answer Must multiple delta H by the same factor What is the enthalpy equation? - Answer H=U+PV What is the system? - Answer Reactants and products (the reaction) What does delta H =? - Answer q (heat) What does q= - Answer s m delta T What is m? - Answer Mass What is s? - Answer Specific heat What is delta T? - Answer The change in temperature (T final- T initial) What is C? - Answer The heat capacity of an object How do we calculate the heat associated with a temperature change? - Answer q=sm delta T What does Calorimetry mean? - Answer The measurement of heat changes What is the specific heat defined as? - Answer The amount of heat required to raise the temperature of 1g of the substance by 1C What is heat capacity defined as? - Answer The amount of heat required to raise the temperature of an object by 1C What are specific heat units? - Answer J/(g*C) What are heat capacity units? - Answer J/C How do we measure qsys= -q surr? - Answer By measuring the temperature change for the surroundings What will delta H depend on? - Answer The amount of matter involved What happens in an exothermic reaction in relation to the system and surroundings? - Answer The system loses heat, and the surroundings gain heat What does Hess's law state? - Answer The change in enthalpy for a stepwise process is the sum of the enthalpy changed for each of the steps What are the four ways to find delta H rxn? - Answer Calorimetry, Hess's law, standard enthalpies of formation, and bond enthalpies What does standard enthalpy of formation (deltaHf) or "heat of formation" mean? - Answer The enthalpy change to form 1 mole of a substance from its constitute elements in their standard states