12.6 to 12.7 (Exam 1)

Question 1

What is thermochemistry?

Answer 1

The study of heat transfers during chemical reactions

Question 2

What is the sign on energy transferred out of the system?

Answer 2

-

Question 3

What is the sign for /\H for an exothermic reaction?

Answer 3

-

Question 4

What is the sign for /\H for an endothermic reaction?

Answer 4

+

Question 5

What does Hess’s Law state?

Answer 5

If two or more chemical reactions are added to form another chemical equation, the corresponding enthalpies of reaction must be added

Question 6

What is the standard state for solids and liquids?

Answer 6

A pressure of 1 atm at a specified temperature

Question 7

What is the standard state for gases?

Answer 7

A pressure of 1 atm at a specified temperature and the exhibition of ideal gas behavior

Question 8

What is the standard state for dissolved species?

Answer 8

A 1 M solution at a pressure of 1 atm and specified temperature, with the exhibition of ideal solution behavior

Question 9

What is the enthalpy of a chemical element at 298.15 K (25* Celsius)?

Answer 9

0

Question 10

If multiple forms of an element exist in the standard state, which one is assigned an enthalpy of 0?

Answer 10

Whichever is the most stable

Question 11

What is standard enthalpy of formation (/*Hf)?

Answer 11

The enthalpy change for the reaction that produces one mole of the compound from its elements in their stable states

Question 12

What is bond enthalpy?

Answer 12

The enthalpy change when a bond is broken in the gas phase

Question 13

What is kept constant in an isothermal process?

Answer 13

Temperature