Bond Energy Calculations

What is the bond energy of a specific bond?

• The bond energy of a specific bond is the average energy required to break that bond in a variety of compounds.

• The bond energy is the total energy released when a bond is formed.

• The bond energy is the energy required to create a bond between two atoms.

• The bond energy is the energy associated with the movement of electrons in a bond.

How can you tell if a reaction is exothermic from its ΔH value?

• If ΔH is positive, the reaction is exothermic, indicating that energy is absorbed.

• If ΔH is zero, the reaction is exothermic, indicating that there is no energy change.

• If ΔH is negative, the reaction is exothermic, indicating that energy is released.

• If ΔH is a large positive number, the reaction is exothermic, indicating that energy is released.

What happens to temperature in an endothermic reaction?

• The temperature of the surroundings increases as the reaction releases heat.

• The temperature of the surroundings decreases as the reaction absorbs heat.

• The temperature remains constant throughout the reaction.

• The temperature of the surroundings fluctuates randomly during the reaction.

What is the difference between endothermic and exothermic reactions?

• Endothermic reactions release energy to the surroundings, while exothermic reactions absorb energy from the surroundings.

• Endothermic reactions absorb energy from the surroundings, while exothermic reactions release energy to the surroundings.

• Endothermic reactions occur only in gases, while exothermic reactions occur in liquids and solids.

• Endothermic reactions are faster than exothermic reactions, which are slower.

What is the role of energy in phase changes?

• Energy is absorbed or released during phase changes, such as melting (endothermic) or freezing (exothermic).

• Energy is only released during phase changes.

• Energy has no effect on phase changes.

• Energy is only absorbed during phase changes.

What does it mean if a reaction has a positive ΔH?

• It indicates that the reaction is exothermic, releasing energy to the surroundings.

• It indicates that the reaction is endothermic, meaning it absorbs energy from the surroundings.

• It indicates that the reaction is at equilibrium, with no net change in energy.

• It indicates that the reaction is spontaneous, occurring without energy input.

What is bond energy?

• The energy required to form a bond between two atoms.

• The amount of energy required to break one mole of a bond in a gaseous substance.

• The energy released when a bond is formed.

• The energy needed to change the state of a substance.

How do you calculate the overall energy change in a reaction?

• Overall energy change = (Total bond energies of bonds broken) + (Total bond energies of bonds formed).

• Overall energy change = (Total bond energies of bonds broken) - (Total bond energies of bonds formed).

• Overall energy change = (Total bond energies of bonds formed) - (Total bond energies of bonds broken).

• Overall energy change = (Total bond energies of bonds broken) * (Total bond energies of bonds formed).

What happens to temperature in an exothermic reaction?

• The temperature of the surroundings increases as the reaction releases heat.

• The temperature of the surroundings decreases as the reaction absorbs heat.

• The temperature remains constant throughout the reaction.

• The temperature fluctuates randomly during the reaction.

What does ΔH represent in a chemical reaction?

• It represents the change in entropy, indicating the disorder of a system.

• It represents the change in enthalpy, indicating the heat absorbed or released during a reaction.

• It represents the change in pressure, indicating the force exerted by the gas.

• It represents the change in volume, indicating the space occupied by a substance.