Midterm 2 (Chapters 5-6) Flashcards
work
the energy used to cause an object to move against a force
heat
the energy used to cause the temperature of an object to increase
equation for kinetic energy
Ek = ½mv^2 (joules)
equation for potential energy
m x g x h
equation for electrostatic energy
Eel = kQ1Q2/d
k = 8.99x10^9 J-m/C^2
what is a joule
joule (J): 1 Kg-m^2/s^2
calorie to joule
1 cal = 4.184 J
open system
one in which matter and energy can be exchanged with the surroundings (e.g. an uncovered pot of boiling water)
closed system
can exchange energy but not matter with their surroundings (e.g. mixture of hydrogen gas and oxygen gas in a cylinder fitted with a piston – energy can enter or leave system as heat or as work done on piston)
isolated system
one in which neither energy nor matter can be exchanged with the surroundings
work equation
w = F x d
F = m x g
w = m x g x d
what is the first law of thermodynamics?
energy is conserved
internal energy
E
ΔE equation
ΔE = Efinal - Einitial ΔE = q + w
examples of state functions
S,G,E,H, temperature, pressure, volume
enthalpy equation
H = E + PV
equation for PV work
w = -PΔV
ΔH equation
ΔH = ΔE + PΔV
ΔH = Hproducts - Hreactants
what is heat capacity
the heat capacity of an object is the amount of heat required to raise its temperature by 1 K or 1 C° - the greater the heat capacity the greater the heat required to produce a given increase in temperature
what is molar heat capacity
the specific heat capacity for one mole of a substance - you get it from the specific heat
equation of specific heat
Cs = q / (m x ΔT)