Definitions Flashcards
Define the definition of a Bomb Calorimeter
- Type of calorimeter
- Virtually eliminates heat loss, so provides very accurate values for enthalpies of combustions
What is the energy required to break a particular bond
Bond dissociation enthalpy
What is Calorimetric?
- Technique used for measuring amount of heat energy absorbed or given out by a reaction
State the chemical reaction during which heat is taken in from the surroundings with its enthalpy change being always positive
Endothermic reaction
State the definition of a Exothermic reaction
The chemical reaction during which heat is given out to the surroundings with its enthalpy change being always negative
State the definition of Enthalpy
A measure of energy stored in a system. Given the symbol heat
State what is meant by Enthalpy Change
The heat energy exchange between the reacting system & its surroundings at constant pressure. Given the symbol DH
State what the Enthalpy Cycle is.
A diagram showing a reaction taking place by 2 or more alternative routes, all of which involve the same enthalpy change, according to Hess’s law.
Also known as a Hess cycle.
What is a Enthalpy level/profile diagram?
A diagram - shows amount of energy contained in both reactions & products for a reaction - therefore shows difference between them
State Hess’s Law
A rule stating that the overall enthalpy change for a reaction is independent of the route the reaction takes
State the definition of Specific Heat Capacity
The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree Kelvin (or Celsius)
State the definition of Standard enthalpy of atomization
The enthalpy change when 1 mole of gaseous atoms of a substance are formed from the substance in its standard state under standard conditions (298 K & 100kPa)
Sate the definition of Standard enthalpy of combustion
The enthalpy change when 1 mole of a substance is completely burnt in oxygen under standard conditions (298 K & 100kPa), with ALL substance being in their standard states
State the definition of Standard enthalpy of formation
The enthalpy change when 1 mole of its constituent elements under standard conditions (298 K & 100kPa), with ALL substances being in their standard states
State the definition of Standard enthalpy of reaction
The enthalpy change for a reaction under standard conditions (298 K & 100kPa), with ALL substances being in their standard states
