Thermodynamics

Question 1

Breaking bonds

Answer 1

Endothermic

Splitting 2 atoms together raises them to higher energy state (input of energy needed)

Delta H> 0

Question 2

Forming Bonds

Answer 2

Releases energy (exothermic)

Bringing 2 atoms together lowers energy (is releasd)

Delta H<0

Question 3

Conduction

Answer 3

Transfer of heat via direct contact

Question 4

Convection

Answer 4

Transfer of heat due to motion of liquid/gas

Question 5

Radiation

Answer 5

Transfer of heat due to EM radiation

Question 6

• W

Answer 6

Increase in volume

System doing work on surroundings

Expansion

Question 7

+ Work

Answer 7

Decrease in volume

Surroundings doing work on system

Compression

Question 8

Standard State Exceptions

Answer 8

H2 gas

C (graphite)

Br2 (liquid)

I2 (solid)

Question 9

3rd Law of Thermodynamics

Answer 9

Entropy of a perfect crystal cooled to 0 K is 0

Question 10

(-) H

(+) S

Answer 10

Negative G

Spontaneous at all temperatues

Question 11

(-) H

(-) S

Answer 11

Sponatneous (-) at low temperatues

Non-spontaneous (+) at high temperatures

Question 12

(+) H

(+) S

Answer 12

Non-spontaneous (+) at low temperatures

Spontaneous (-) at high temperatures

Question 13

(+) H

(-) S

Answer 13

Non-spontaneous (+) at all temperatures

Question 14

Collsion Theory

Answer 14

For a reaction to occur:

Molecules must collide

Molecules must have proper orientation when they collide

Molecules must have sufficient energy to overcome the activation energy barrier