Chemistry Thermodynamics - Test 7

state

energy is a ____ function

state function

means that it does not matter how we get there (independent of pathway)

1st law

energy cannot be created or destroyed

1st law

any change in energy of a system must be balanced by a transfer of energy either into or out of the system

q

heat symbol

heat

transfer of thermal energy between 2 objects at different temperatures

T

temperature symbol

temperature

measure of the particle motion in a system

temperature

proportional to the kinetic energy of the particles

endothermic

addition of energy is required (products have more energy)

+H

temperature will go down

-H

temperature will go down

exothermic

energy is released (products have less energy)

-H

endothermic (enthalpy)

+H

exothermic (enthalpy)

heat, work

2 ways to transfer energy

+q

endothermic (heat symbol)

-q

exothermic (heat symbol)

endothermic

heat added to the system

exothermic

heat released from the system

+w

work done on system

-w

work done by system

E

= q + W

W

work

+E

+q + w

-q - w

-E

+q - w

-q + w

E

= qp = H

enthalpy

flow of heat at constant pressure

heat

you can view ____ as a reactant/product

exothermic

reactants —> products + heat = ____ reaction

endothermic

reactants + heat → products = _____ reaction

endothermic

ice —> water —> steam

exothermic

stream —> water —> ice

vaporization 

_____ > H fusion

vaporize

it takes more energy to ____ because IMFs (H bonds_ are completely broken

endothermic

expanding solute, separating cations are ions:

-H1

endothermic

expanding solvent/separate H2O molecules (weakens H bonds):

+H2

exothermic

allow solute and solvent to interact/H2O molecules solvate ions:

-H3

hot to cold

heat will flow from ______ until temperatures are the same

q

is the heat transferred

H

is the heat transferred per mole

calorimetry

a process of measuring heat based on observing temperature change

specific heat capacity

energy required to raise the temperature of 1g by 1C

4.184 J/gxC

H2o C

up

q is less than zero when temp goes ___

exothermic

down

q is greater than zero, temp goes ____

endothermic

m

mass (g)

c

specific heat capacity (J/gxC)

T

change in temperature

enthalpy of fusion

energy required to melt a substance, or energy given off when you freeze a substance 

KJ/mol, KJ/g

units for enthalpy of fusion/vaporization

enthalpy of vaporization

energy required to vaporize a substance or to condense a substance

specific heat capacity

energy required to heat a substance, usually given in J/gxC

endothermic

exothermic