Chem Thermo

Question 1

Zeroth law of thermodynamics

Answer 1

If two systems are in equilibrium with a third, the two initial systems are in equilibrium with each other. Temperatures are the same. Heat will flow high to low

Question 2

1st law of thermodynamics

Answer 2

Total energy of universe is constant. Energy can be transformed from one form to the other but cannot be destroyed

Question 3

Does an isolated system have constant energy?

Answer 3

Yes

Question 4

What increases energy?

Answer 4

Work

Question 5

2nd Law of Thermodynamics

Answer 5

Disorder of the universe increases spontaneously

Question 6

What is entropy?

Answer 6

Disorder.

Question 7

What is enthalpy?

Answer 7

Measure of heat energy that is released or absorbed when bonds are broken or formed during a reaction that is run at constant pressure

Question 8

If entropy is less than zero, what happened to energy?

Answer 8

It was released to form bond

Question 9

If enthalpy is more than to break it what happened to energy?

Answer 9

Energy is absorbed and enthalpy is greater than zero to break bond

Question 10

What are things that effect enthalpy?

Answer 10

Phase change, formation of strong molecular forces, breaking covalent bonds

Question 11

What is heat of formation?

Answer 11

Energy required to make 1 mole of a compound from its constituent elements in their natural or standard state

Question 12

If heat of formation is positive what does this mean for the compound?

Answer 12

Input of heat is required to make compound from constituent elements

Question 13

If heat of formation is negative what does this mean for the compound?

Answer 13

Gives off energy to be made

Question 14

Hess Law

Answer 14

If reaction occurs in several steps sum of energies absorbed or given off in all steps will be same as that for the overall reaction

Question 15

Is enthalpy dependent on pathway of reaction?

Answer 15

No it is a state function.

Question 16

If creating a bond is enthalpy positive or negative?

Answer 16

Negative and exothermic

Question 17

If breaking a bond is enthalpy positive or negative?

Answer 17

Positive endothermic

Question 18

If wanting to calculate enthalpy of the reaction what should one use?

Answer 18

Bond dissociation energy

Question 19

Third law of thermodynamics

Answer 19

Absolute zero is state change of entropy

Question 20

Is entropy dependent on temperature?

Answer 20

Yes

Question 21

What energy determines kinetics?

Answer 21

Activation energy

Question 22

If free energy is negative, is the reaction spontaneous or nonspontaneous

Answer 22

Spontaneous

Question 23

If delta G is equal to zero what does this tell us?

Answer 23

Reaction is at equilibrium

Question 24

If delta G is greater than zero what does this tell us?

Answer 24

Reaction is nonspontaneous