Class Summary Thermochemistry (1)

What is solution stoichiometry?

It involves calculations based on the stoichiometry of chemical reactions in solutions.

What do characteristic acids typically release in solution?

Hydrogen ions (H+).

What is thermochemistry?

The branch of chemistry that deals with the study of heat energy associated with chemical reactions.

What is the formula for internal energy?

ΔE = q + w, where ΔE is the total change in internal energy, q is heat exchanged, and w is work done.

What does a positive sign for internal energy indicate?

Energy entering the system (heat absorbed, q>0).

What does a negative sign for internal energy indicate?

Energy leaving the system (heat given off, q

What is the first law of thermodynamics?

Energy cannot be created or destroyed; the change in internal energy equals the energy lost by the system and gained by the surroundings.

What occurs during an endothermic reaction?

The system absorbs energy from its surroundings in the form of heat.

What occurs during an exothermic reaction?

The reaction releases energy from the system in the form of heat.

What is the equation for enthalpy (ΔH)?

ΔH = E + PV, where E is internal energy, P is pressure, and V is volume.

What is the nature of the forward reaction when converting SO₂ to SO₃?

It is exothermic with an enthalpy change of -198.2 kJ/mol.

What is the nature of the reverse reaction when converting SO₃ to SO₂?

It is endothermic with an enthalpy change of +198.2 kJ/mol.