W2 Flashcards
What are a few measurable quantities?
Temperature
Pressure
Volume
Energy
What is a zero point
(Absolute 0)
Lowest temperature in the universe
0K = -273C
Absolute temperature
273.15C
Absolute temperature
273.15C
What is ideal gas
Obeys the relationship of PV=nRT
Pressure equations
P = nRT/V
P = force/area
Standard conditions
273C and 1.00x10^5Pa
How to work out total pressure of 2 gases
P = (no.mol gas 1 + no.mol gas 2) / 1 and all X RT/V
Diatheramal
Allow only heat transfer
Diatheramal
Allow only heat transfer
Adiabatic
Heat doesn’t enter or leave
Isothermal
Having a constant or the same temperature
Dalton’s law
In a mix of non-reacting gases, the total pressure exerted is equal to sum of partial pressure of each gas
Enthalpy equation
H = E + PV
Exothermic
Produce heat
Triangles < 0
Endothermic
Absorbs heat
TriangleH > 0
How to calculate standard enthalpies of a reaction
Products - reactants
Use their enthalpies or formations - given
When calculating standard enthalpy of a reaction what is a rule for pure elements
Pure elements with have an enthalpy of formation of 0
Ie 7O2 would be 0kj/mol
How to work out enthalpy of combustion
Same as enthalpy standard
Products - reactants
What is Hess law
The standard enthalpy of an overall reaction is the sum of all standard enthalpies of individual reactions
Ie
1) A+B=C 100J
2) C+D=E 200J
So 3) A+B+D=E
The C’s cancel out and we added 1 and 2 to get 3 so add the enthalpies:
100J + 200J = 300J
Heat capacity equation
Ch = Heat absorbed / change in T
Specific heat capacity equation
Cs = heat absorbed / ( mass x change in T )
Molar heat capacity equation
Cm = heat absorbed / ( mols x change in T )
