Energy

Question 1

What is Energy?

Answer 1

the capacity to do work or supply heat

Question 2

Potential Energy

Answer 2

stored potential

Question 3

Kinetic Energy

Answer 3

active motion

Question 4

What is the first law of thermodynamics?

Answer 4

Energy is conserved
it cannot be created or destroyed
it can be transferred or transformed

Question 5

Enthalpy (H)

Answer 5

total energy of the molecule
the sum of potential and kinetic energy

Question 6

types of kinetic energy

Answer 6

thermal
mechanical
electrical
magnetic

Question 7

types of potential energy

Answer 7

chemical
elastic
nuclear
gravitational

Question 8

true or false: strong bonds have low potential energy

Answer 8

true

Question 9

true or false: weak bonds have high potential energy

Answer 9

true

Question 10

name bonds that have high potential energy

Answer 10

C-H
C-C

Question 11

how is kinetic energy measured?

Answer 11

temp

Question 12

if an object has a low temp:

Answer 12

molecules are moving slowly
is cold

Question 13

if an object has a high temp:

Answer 13

molecules are moving rapidly
is hot

Question 14

Entropy (S)

Answer 14

the amount of disorder in a group of molecules

Question 15

what is the second law of thermodynamics?

Answer 15

total entropy always increases in isolated systems

Question 16

when does chemical equilibrium occur?

Answer 16

when the forward and reverse reactions proceed at the same rate
when the quantities of reactants and products remain constant

Question 17

when is a chemical reaction spontaneous?

Answer 17

they proceed without any continuous external influence
no added energy is needed

Question 18

is a spontaneous reaction fast or slow?

Answer 18

could be either

Question 19

non-spontaneous reaction depends on:

Answer 19

continuous external influence
needs energy

Question 20

Spontaneity of a reaction depends on

Answer 20

1.The change in potential energy (deltaH)
Products often have less potential
energy than the reactants (deltaH) decrease

2. The degree of order (deltaS)
   Products are less ordered than the
   reactants (deltaS) increase

Question 21

Gibbs free energy change deltaG

Answer 21

deltaG = deltaH-TdeltaS
deltaH : difference in enthalpy (total energy of
molecules)
deltaS : difference in entropy (disorder)
T : temperature

Spontaneous reaction (exergonic) delta G <0
Non-spontaneous reaction (endergonic) delta G>0