CHEM 125 Cal Poly Exam Questions And
Correct Answers
1. How does matter possess energy? - ANSWER Kinetic Energy (KE): the energy an object
possesses by virtue of its motion.
Potential Energy (PE): the energy an object possesses as a result of its composition or its
position.
2. How is energy transferred? - ANSWER Law of conservation of energy
Exothermic processes - ANSWER Energy (heat) is given off
Making chemical bonds
Ice freezing
Metabolism of sugar
Combustion Reactions
Anything that produces energy
Negative (-) enthalpy
Endothermic processes - ANSWER Energy (heat) is absorbed
Breaking chemical bonds
, Ice melting
Baking cookies
Anything that absorbs energy
Positive (+) enthalpy
Calorimetry - ANSWER The heat gained by the calorimeter = heat lost by the chemical system
The heat lost by the calorimeter = heat gained by the chemical system
Heat capacity (C): - ANSWER The amount of energy required to raise the temperature of a
substance by 1 K (1°C).
Specific heat capacity (specific heat, c or Cs) - ANSWER The amount of energy required to
raise the temperature of 1 g of a substance by 1 K.
Molar heat capacity (C molar): - ANSWER The amount of energy required to raise the
temperature of 1 mol of a substance by 1 K.
The heat gained by the solution, qsoln, is equal in magnitude to the heat of the reaction, qrxn,
but opposite in sign. - ANSWER qsys = qsoln + qrxn = 0 when there is no loss of heat to the
surroundings
qrxn = Cs x m x ΔT = qsoln
Correct Answers
1. How does matter possess energy? - ANSWER Kinetic Energy (KE): the energy an object
possesses by virtue of its motion.
Potential Energy (PE): the energy an object possesses as a result of its composition or its
position.
2. How is energy transferred? - ANSWER Law of conservation of energy
Exothermic processes - ANSWER Energy (heat) is given off
Making chemical bonds
Ice freezing
Metabolism of sugar
Combustion Reactions
Anything that produces energy
Negative (-) enthalpy
Endothermic processes - ANSWER Energy (heat) is absorbed
Breaking chemical bonds
, Ice melting
Baking cookies
Anything that absorbs energy
Positive (+) enthalpy
Calorimetry - ANSWER The heat gained by the calorimeter = heat lost by the chemical system
The heat lost by the calorimeter = heat gained by the chemical system
Heat capacity (C): - ANSWER The amount of energy required to raise the temperature of a
substance by 1 K (1°C).
Specific heat capacity (specific heat, c or Cs) - ANSWER The amount of energy required to
raise the temperature of 1 g of a substance by 1 K.
Molar heat capacity (C molar): - ANSWER The amount of energy required to raise the
temperature of 1 mol of a substance by 1 K.
The heat gained by the solution, qsoln, is equal in magnitude to the heat of the reaction, qrxn,
but opposite in sign. - ANSWER qsys = qsoln + qrxn = 0 when there is no loss of heat to the
surroundings
qrxn = Cs x m x ΔT = qsoln
