Enthalpy change

Cards (11)

What is standard enthalpy change of a reaction?
The enthalpy change when a reaction occurs in the molar quantities shown in the chemical equation, under standard conditions
What is the standard enthalpy change of formation?
The enthalpy change when 1 mole of a compound forms from its constituent elements under standard conditions.
What is the standard enthalpy change of combustion?
The enthalpy change when 1 mole of a substance combust fully in oxygen under standard conditions.
What is standard enthalpy change of neutralisation?
The enthalpy change when an acid and alkali neutralise under standard conditions, to for 1 mole of water.
What happens in an exothermic reaction?
Energy is given out to surrounding, temperature increases (- $\Delta$ H)
What happens in an endothermic reaction?
Energy is taken in from surroundings, temperature decreases (+ $\Delta$ H)
What is enthalpy?
A measure of the heat content stored in a chemical system at a constant pressure.
What is enthalpy change?
Enthalpy change refers to the heat energy absorbed or released during a chemical reaction or physical process at constant pressure. It is denoted as ΔH and is a measure of the change in the internal energy of a system.
What are the standard conditions?
temp= 298 K and pressure= 100kPa
What is specific heat capacity?
Specific heat capacity is the amount of heat energy required to raise the temperature of a substance by a certain amount.
What is the equation for enthalpy change?
a=mc $\Delta$ t