Chemistry - Enthalpy

Front

What is Enthalpy?

Back

Energy stored in the chemical bonds in a substance.

Front

What type of reaction is characterized by the release of heat?

Back

Exothermic reaction.

Front

What type of reaction absorbs heat from the surroundings?

Back

Endothermic reaction.

Front

In an exothermic reaction, is heat a product or a reactant?

Back

Product.

Front

How do you calculate the Enthalpy change of a reaction?

Back

ΔH = ΔH_products - ΔH_reactants.

Front

What does a positive ΔH value indicate about a reaction?

Back

The reaction is endothermic.

Front

What does a negative ΔH value indicate about a reaction?

Back

The reaction is exothermic.

Front

What is the unit of Enthalpy?

Back

Joules (J) or kilojoules (kJ).

Front

What is the significance of the enthalpy of formation?

Back

It is the change in enthalpy when one mole of a compound is formed from its elements in their standard states.

Front

What is the relationship between Enthalpy and temperature in a reaction?

Back

Enthalpy changes can affect the temperature of the system.