ENERGETICS
- Created by: Retroxlight
- Created on: 31-05-16 02:02
View mindmap
- ENERGETICS
- Hess's law
- The enthalpy change for a reaction is independant of the route
- Provided the starting and final conditions and reactants an products are the same
- Energy Cycles
- ?H(3) = ?H(1) + ?H(2)
- ?Hi, first ionization energy
- Eg: Li ion batteries
- min. energy required to remove 1 mol of electrons from 1 mol of gaseous atoms
- ?Hlat, lattice enthalpy
- Eg: Amonium chloride, is part of the Solvay process used to produce sodium carbonate. It is formed by combining ammonia gas and hydrogen cloride gas.
- ?H when 1 mol of a solid ionic compound is separated into gaseous ions under standard conditions
- Born- Haber cycle
- ?He, first electron affinity
- Eg: the Cl ion is an essential electrolyte located in all body fluids responsible for maintaining acid/base balance.
- ?H when 1 mol of gaseous electrons is added to one mol of gaseous atoms
- The enthalpy change for a reaction is independant of the route
- Entropy & Spontaneity
- Law of Conservation of Energy
- Energy cannot be created or destroyed, only transformed from one form to another.
- Enthalpy
- Bond Enthalpy
- Energy needed to break 1 mol of bonds in gaseous molecules under standard conditions
- ?H = ?E (bonds broken) - ?E(bonds formed)
- The heat content of a system
- A System is the area of interest
- Open System
- Can exchange energy and matter with the surroundings
- Eg: The Earth
- Closed System
- Can exchange energy but not matter with the surroundings
- Eg: closed cooler
- The Surroundings are everything else in the universe
- Open System
- A System is the area of interest
- Enthalpy Change
- Exothermic
- Heat is given out by the system
- Enthalpy of reaction is negative
- Eg: Nuclear fission
- Endothermic
- Heat is absorbed by the system
- Enthalpy of reaction positive
- Eg: Photosynthesis
- Standard Conditions
- 100 kPa pressure
- 1 mol dm^-3 concentrationsfor all solutions
- All substances in their standard states
- q = m*c*?T
- Specific Heat Capacity of Water is 4.18
- Heat capacity is the heat needed to increase the temperature of an object by 1 K.
- Assumptions being made
- No heat loss from system
- Water absorbs all heat
- Water density is 1.00g cm^-3
- Standard ?H of formation
- ?H when 1 mol of the substance is formed from its elements in their standard states under standard conditions
- Eg: During the extraction of Fe in a blast furneace, the C(s) released is combined with Oxygen(g), forming Carbon Dioxide
- ?H = sum of ?Hf(products) - sum of ?H (reactants)
- ?Hatom, Enthalpy of atomization
- Eg: The reaction between Mg and sulfuric acid for the production of magnesium sulfate for medical purposes, H gas is produced.
- ?H when 1 mol of gaseous atoms is formed from the element in its standard state.
- Exothermic
- Bond Enthalpy
- Hess's law
Similar Chemistry resources:
Teacher recommended
Comments
No comments have yet been made