Thermochemistry

Question 1

Enthalpy, Entropy, and Gibb’s Free Energy

Answer 1

• Negative change in enthalpy means exothermic
• Positive change in entropy means increase in disorder
• Negative change in Gibb’s free energy is spontaneous

Question 2

Bond Energies

Answer 2

• Energy is absorbed when breaking bonds, and released when forming bonds
• Can calculate enthalpy of a reaction by subtracting the energy of bonds broken by bonds formed

Question 3

Heat Energy

Answer 3

• q = mCΔT

Question 4

Heat Transfer By:

Convection

Conduction

Radiation

Evaporation-Condensation

Answer 4

• Convection is the movement of heat through a fluid medium (gas, liquid)
• Conduction is the transfer of heat through direct contact 9vibrational energy is transferred via collisions between neighboring molecules)
• Radiation is the emission of photon energy in the form of electromagnetic waves
• Evaporation is an endothermic process in which a liquid absorbs heat and is converted into a gas while condensation is an exothermic process wherby heat is released from a gas as it is converted into a liquid