Module 13

Question 0

In an endothermic reaction, is energy considered a reactant or a product?

Answer 0

Reactant

Question 1

In an exothermic reaction, is energy considered a reactant or product?

Answer 1

Product

Question 2

Enthalpy

Answer 2

The energy stored in a substance

Question 4

Change in Enthalpy (ΔH)

Answer 4

The energy change that accompanies a chemical reaction.

Question 5

Is ΔH positive or negative for endothermic reactions?

Answer 5

Positive

Question 6

Is ΔH positive or negative for exothermic reactions?

Answer 6

Negative

Question 7

ΔH=

Answer 7

Energy required to break bonds - Energy released when bonds form

Question 8

Hess’s Law Equation

Answer 8

ΔΗ°= Σ ΔΗf° (products) - Σ ΔΗf° (reactants)

Question 9

Enthalpy of formation (ΔΗf)

Answer 9

The ΔΗ of a formation reaction

Question 10

What is the standard Enthalpy of formation of an element in its elemental form?

Answer 10

Zero

Question 11

Hess’s Law

Answer 11

Enthalpy is a state function and is therefore independent of path

Question 12

Activation energy

Answer 12

The energy necessary to start a chemical reaction

Question 13

Entropy

Answer 13

A measure of the disorder that exists in any system

Question 14

The Second Law of Thermodynamics

Answer 14

The entropy of the universe must always either increase or remain the same. It can never decrease.