Exam 5 Flashcards
Kinetic energy
Energy of motion
Potential energy
Stored energy
SI unit of energy
Joule
First law of thermodynamics
energy cannot be created or destroyed; it can only be converted from one form to another
state function
the only part that matters is the start and the end, not the steps of how you got there
energy is a ________ function
state
what does + heat mean in a reaction
endothermic (heat in)
what does (-) heat mean in a reaction
exothermic (heat out)
Endothermic (sign?)
heat in (+)
Exothermic (sign?)
heat out (-)
what does C stand for
Heat capacity
what does Cs stand for
Specific heat capacity
q (heat) = (is pretty much the same as)
ΔH Enthalpy (at constant pressure)
ΔHrxn = ΔHfinal - ΔHinitial
Hess’s Law
enthalpies are additive
Standard state conditions
P = 1 atm
T = 25°
Concentration = 1M
1atm = ? mmHg
1atm = ? Torr
760 mmHg
760 Torr
ΔH°f
Enthalpy of formation
Enthalpy of formation
The energy required to form 1 mol of a substance from its elements in their standard state
Calorimetry
the process of measuring the amount of heat released or absorbed during a chemical reaction
Pressure
the force exerted by molecules on or against another body
SI unit for pressure
atm
what are the 4 simple gas laws
Boyles law, Charles law, Avogadro’s law, Daltons law
Boyles law
(proportionality?)
P and V are related
(at constant T)
(inversely proportional)
P₁V₁ = P₂V₂
Charles law
(proportionality?)
V and T are related
(at constant P)
(directly proportional)
V₁ / T₁ = V₂ / T₂
Avogadros law
(proportionality?)
V and n are related
(at constant T and P)
(directly proportional)
V₁ / n₁ = V₂ / n₂
Daltons law
Pₜ = P₁ + P₂ + P₃
what units of temperature are needed to use the gas laws
Kelvin
Ideal gas law equation
PV = nRT
units = atm, L, mol, K
what are the assumptions for the ideal gas law
- Molecules have no volume
(due to the molecules being so far apart) - Molecules do not interact with each other
STP
Standard Temperature and Pressure
T = 0°C
P = 1 atm
STP vs standard state conditions
STP is for gas law equations, standard state conditions are for thermodynamics equations
Molar volume (volume occupied by 1 mole of any gas at STP)
22.4 L
Kinetic molecular theory of gasses
the theory of moving molecules
theory states:
1. molecules have no volume
2. the average KE of a molecule is proportional to its T (in K)
how does molecular speed, temperature and energy apply to KMT
if speed is high, KE is high
if T is high, KE is high
Diffusion
random movement of molecules to spread out and fill space
q (equation) =
c * m * ΔT
ΔH (in relation to q)=
q/mol
ΔH = ΔH(products) - ΔH(reactants)
KE =
1/2 * m * v^2
what makes a gas a real gas
high P
low T
Assumptions for the ideal gas law
- molecules have no volume
- molecules do not interact with each other
what is the unit of heat needed to raise 1 g of a substance 1° C
specific heat capacity
