Electrochemistry
- Electrochemistry
Learning Objectives(a) describe and explain redox processes in terms of electron transfer and/or of changes in oxidation number (oxidation state) (b) define the terms: (i) standard electrode (redox) potential (ii)...
- How To Balance Ionic Equations In Alkaline Medium?
(I) Standard Electrode Potential What information can we obtain from SEP? Sign – oxidation or reduction favoured Magnitude – the extent the reaction is favoured How to measure SEP? - connecting the redox couple (half cell) to SHE. - learn to draw...
- Electrochemistry : 10.1 Galvanic Cell (continued)
SPONTANEOUS REACTION occurs as the result of different ability of metal to give up their electron to flow through the circuit. CELL POTENTIAL (ECell) different in electrical potential of electrodes also called voltage or electromotive...
- Thermochemistry : 9.3 Born-haber Cycle
First Ionization Energy (IE1)Energy required for 1 mol of gaseous atom to lose 1 mol of electrons. Affinity Electron (EA) Energy change that occurs when 1 mol of gaseous atom gains 1 mol of electrons. Lattice EnergyEnergy change when 1 mol of solid...
- Key Terms In Chapter 9
Enthalpy Change: Heat given off or absorbed during a reaction at constant pressure. Exothermic: Gives off heat from system to surroundings. Endothermic: Absorbs heat from the surrounding to the system. Specific Heat Capacity: Amount of heat required to...
Electrochemistry
Thermochemistry : 9.2 Hess Law
- Hess's Law of Heat Summation
ΔH1 =ΔH2 + ΔH3
- Application Using Hess's Law
- To find ΔH of any reaction for which we can write on equation, even if it is impossible to carry out.
- Two methods of calculation
- Algebraic method
- Energy cycle method
- Algebraic method
- To find ΔH of any reaction for which we can write on equation, even if it is impossible to carry out.
- Algebraic Method
- Important steps:
- Identify the target equation whose ΔH unknown.
- Rearrange the equations given mole of reactants and products are on the correct side.
- Add the equation to obtain the target equation all other substances must cancel.
- Identify the target equation whose ΔH unknown.
- Standard Enthalpy of Formation (ΔHf)
- Heat change when 1 mol of a compound is produced from its elements in their standard states.
- ΔHf
of Elements- In its standard states
- ΔHf of Compounds
- Most compound have negative ΔHf
- The compound is more stable than its components elements.
- Determining ΔHrxn From ΔHfaA + bB = cC + dD
Hrxn = [cΔHf (C) + dΔHf (D) – aΔHf (A) + bΔHf (B)]
Hrxn = ( sum of ΔHf of all of the products ) – ( sum of ΔHf of all of the reactant )
- Electrochemistry
Learning Objectives(a) describe and explain redox processes in terms of electron transfer and/or of changes in oxidation number (oxidation state) (b) define the terms: (i) standard electrode (redox) potential (ii)...
- How To Balance Ionic Equations In Alkaline Medium?
(I) Standard Electrode Potential What information can we obtain from SEP? Sign – oxidation or reduction favoured Magnitude – the extent the reaction is favoured How to measure SEP? - connecting the redox couple (half cell) to SHE. - learn to draw...
- Electrochemistry : 10.1 Galvanic Cell (continued)
SPONTANEOUS REACTION occurs as the result of different ability of metal to give up their electron to flow through the circuit. CELL POTENTIAL (ECell) different in electrical potential of electrodes also called voltage or electromotive...
- Thermochemistry : 9.3 Born-haber Cycle
First Ionization Energy (IE1)Energy required for 1 mol of gaseous atom to lose 1 mol of electrons. Affinity Electron (EA) Energy change that occurs when 1 mol of gaseous atom gains 1 mol of electrons. Lattice EnergyEnergy change when 1 mol of solid...
- Key Terms In Chapter 9
Enthalpy Change: Heat given off or absorbed during a reaction at constant pressure. Exothermic: Gives off heat from system to surroundings. Endothermic: Absorbs heat from the surrounding to the system. Specific Heat Capacity: Amount of heat required to...