Thermochem

Question 1

energy:

Answer 1

the ability to do work

Question 2

potential energy:

Answer 2

stored energy (within the bonds in chem)

Question 3

kinetic energy:

Answer 3

energy due to motion

Question 4

enthalpy:

Answer 4

heat absorbed or released through a chemical rxn

Question 5

thermal enthalpy:

Answer 5

energy generated by heat (ET = Eg + Ek)

Question 6

temperature:

Answer 6

a measure of avg kinetic energy
(EK ⬆️, temp ⬆️)
- measure w thermometer

Question 7

heat:

Answer 7

energy transferred from 1 substance to another due to temp difference between them

Question 8

open system:

Answer 8

exchanges both MATTER and ENERGY w surroundings (ex: open rxn flask)

Question 9

closed system:

Answer 9

exchanges only ENERGY w surroundings (matter remains fixed)

Question 10

isolated system:

Answer 10

doesn’t exchange ENERGY NOR MATTER w surroundings

Question 11

law of conservation of energy:

Answer 11

energy is not created or lost. it is transferred (heat lost by one = heat gained by another)

Question 12

specific heat capacity

Answer 12

amount of heat required to raise the temp of the unit mass of a given substance by a given amount

Question 13

endothermic:

Answer 13

rxns that require heat from surroundings (lower in temp)

-if more energy is needed to break reactant bonds compared to the amount of energy released in making new product

Question 14

exothermic:

Answer 14

rxns that release heat (up in temp)

-if more energy is released in making new product bonds than amount needed to break original reactant bonds

Question 15

hess’ law

Answer 15

change in enthalpy is equal to sum of each individual rxn

- (no matter the amount of steps or intermediate rxns)

Question 16

standard state:

Answer 16

reference point for a material

- state properties in thermal dynamics

Question 17

standard heat formation

Answer 17

change of enthalpy during formation of 1 mole of a substance in standard heat