Chapter 5

Question 1

energy

Answer 1

capacity to do work/transfer heat

Question 2

thermodynamics

Answer 2

study of energy and transformations (chemical, mechanical, electrical, etc.)

Question 3

thermochemistry

Answer 3

relationships b/w chemical reactions and energy changes that involve heat
Potential energy- from position

Question 4

electrostatic potential energy

Answer 4

interactions b/w charged particles

Question 5

E(el) =

Answer 5

(kQ1Q2) / d
- Q1/Q2 = electrical charges (2 charge particles)
- d = distance
- k = 8.99 x 10^9 J (m/c^2)
- 1 J = 1 kg m^2/s^2

Question 6

1st law of thermodynamics

Answer 6

energy can be converted from 1 form to another but it is neither created nor destroyed

Question 7

making bonds

Answer 7

releases energy

Question 8

breaking bonds

Answer 8

consumes energy

Question 9

system

Answer 9

portion we single out to study

Question 10

open system

Answer 10

exchange heat and mass w/ surroundings

Question 11

closed system

Answer 11

only exchange heat (not mass) w/ surroundings

Question 12

isolated system

Answer 12

doesn’t exchange heat or mass w/ surroundings

Question 13

internal energy

Answer 13

sum of all kinetic and potential energy of system

Question 14

∆E =

Answer 14

Change in E
∆E = E(final) – E(initial)
∆E = q + w

Question 15

(+) = E(final) > E(initial)

Answer 15

System gained/absorbed energy from surrounding

Question 16

(-) = E(final)) < E(initial)

Answer 16

System lost energy to surrounding

Question 17

q=

Answer 17

sum of heat added to/liberated from system
- (+) = system gains heat
- (-) = systems loses heat

Question 18

w=

Answer 18

work done on/by system
- (+) = work is done on system
- (-) = work is done by system

Question 19

endothermic

Answer 19

system absorbs heat from surroundings
- ∆H = (+)

Question 20

exothermic

Answer 20

system releases heat into surrounds
- ∆H = (-)

Question 21

state functions

Answer 21

we only care about start & end points; not how we got there

Question 22

work

Answer 22

chemical or physical energy –> mechanical work w/ change in volume

Question 23

pressure-volume work; W=

Answer 23

W = -P∆V
∆V = V(initial)-V(final)

Question 24

enthalpy (H); ∆H

Answer 24

heat at constant pressure
- ∆H = ∆E + P∆V

Question 25

∆H = (+)

Answer 25

system gained heat = endothermic

Question 26

∆H = (-)

Answer 26

system released heat = exothermic

Question 27

∆H(rxn)=

Answer 27

H(products) = H(reactants)

Question 28

calorimetry

Answer 28

measurement of heat of flow (∆H)

Question 29

calorimeter

Answer 29

device to measure heat flow

Question 30

qsolution =

Answer 30

(msolution)( ∆T)(Cs) = -qrxn

Question 31

bomb calorimetry; qrxn =

Answer 31

qrxn = Ccal x ∆T
- Ccal = constant (bomb only)

Question 32

heat capacity (C)

Answer 32

energy to raise temp of object 1 d K (1 d C)

Question 33

Specific heat capacity Cs=

Answer 33

heat capacity of 1 gram of substance
- Cs = q / (m x ∆T)

Question 34

Molar heat capacity (Cm)

Answer 34

heat capacity of 1 mole of substance

Question 35

Specific quantity

Answer 35

known mass m of substance gains/loses heat

Question 36

Hess’s Law: ∆Hrxn =

Answer 36

∆Hrxn = sum of ∆H for each step

Question 37

enthalpies of formation (∆Hf)

Answer 37

∆Hf = (n)(∆H)(Hproducts) - (m)(∆H)Hreactants

Question 38

bond enthalpy

Answer 38

∆H for breaking of a particular bond in 1 mole of gaseous substance

Question 39

fuel value

Answer 39

energy released when 1 g food in combusted