Thermochemistry

Question 0

What was the sequence in how the sun produced all energy on earth

Answer 0

1) ancient organisms stored solar energy during photosynthesis
2) ancient organisms ate the other organisms and when the died, their remains were trapped in sediment, and intense heat+pressure turned it into oil, gas, waxes, tars

Question 1

Where did all energy originate?

Answer 1

The sun

Question 2

What are the two fundamental types of energy in chemistry

Answer 2

1) kinetic energy (Ek): the energy of motion (of particles,heat)
2) potential energy (Ep): energy that is stored (in chemical bonds)

Question 3

What does the first law of thermodynamics state

Answer 3

A) the total energy of the universe is constant
B) energy can be converted to other forms, but the total energy of the system is conserved (can’t be created or destroyed)

Question 4

What does the second law of thermodynamics state

Answer 4

A) Without energy input, a system becomes more disordered

B) heat will always transfer from hot to cold until thermal equilibrium is reached

Question 5

What is enthalpy

Answer 5

The sum of all forms of kinetic and potential energy in a system (Ek+Ep)

Question 6

When do changes in enthalpy occur?

Answer 6

When heat is released or absorbed in a physical, chemical, or nuclear change

Question 7

What is Enthalpy change measured in, what is the symbol for enthalpy change?
How is the symbol sometimes altered?

Answer 7

Enthalpy change is

Question 8

What is molar enthalpy?
What is the symbol
What unit is it measured in?

Answer 8

Enthalpy change per mile of a substance