Chapter 5-thermochemistry

Question 1

law of conservation of energy

Answer 1

energy can neither be created nor destroyed, but only changed in form

Question 2

work

Answer 2

energy used to cause an object to mover against a force

Question 3

energy

Answer 3

ability to do work

Question 4

heat

Answer 4

most important energy form, causes temp increase

Question 5

thermodynamics

Answer 5

the study of heat

Question 6

thermochemistry

Answer 6

energy chnages that accompany physical/chemical properties

Question 7

kinetic energy

Answer 7

KE=1/2mv^2

Question 8

potentional energy

Answer 8

positon

Question 9

internal energy

Answer 9

PE+KE in a system

Question 10

1 joule =

Answer 10

1 kg m^2/sec^2

Question 11

1 calorie

Answer 11

4.184 joules

Question 12

1 joule =

Answer 12

9.48 x 10^-4 BTU

Question 13

1 electron volt

Answer 13

3,8 x 10 ^-20 cal

Question 14

specific heat

Answer 14

physical propery, intensive

amount of heat required to raise the temp of 1 g of a substance 1 degree C

Question 15

heat capacity

Answer 15

physical property, extensive, changes with sample size

overall effect of heat ont he temp of a substance, thermal capacity of the whole

Question 16

heat

Answer 16

q

given off, exothermic (-)

absorbed, endothermic (+)

see chart in notes

Question 17

calorimetry

Answer 17

the change in temp caused by a rxn combined with the values of the specific heat and the mass of the reacting system make it possible to determine the dH of a rxn experimentally

Question 18

calorimeter

Answer 18

vessel for determing dH of a rxn

Question 19

enthalpy

Answer 19

heat content state function, determined by dH

H final-H initail

if value is negative, exothermic

if positive, endothermic

Question 20

hess’s law

Answer 20

for any rxn that can be expresssed as the sum of 2 or more rxns, the heat of rxn (dH) is a result of the algebraic sums of the rxn