Test 3: Energy

Question 1

Compounds with high overall energy are considered to have __

Answer 1

potential energy (a potential for the energy to be released)

Question 2

Energy is stored inside a compound by __

Answer 2

chemical bonds

Question 3

Types of potential energy (2)

Answer 3

Enthalpy and entropy

Question 4

Enthalpy is the measure of __, or the energy in __ form that is __ in a physical or chemical process

Answer 4

heat energy; heat; released or absorbed

Question 5

Enthalpy is frequently represented by the term __.

Answer 5

(triangle symbol)^H; the triangle means “change in” and the “H” means heat energy

Question 6

If ^H is negative than heat was

Answer 6

released by the reaction or process (exothermic)

Question 7

exothermic

Answer 7

heat was released by the reaction or process (resulting in a negative ^H)

Question 8

If ^H is positive then heat was

Answer 8

absorbed by the reaction or process (endothermic)

Question 9

Endothermic

Answer 9

heat was absorbed by the reaction or process

Question 10

Heat is best described as __(2) movement.

Answer 10

atomic and molecular

Question 11

The more movement energy a substance has the more __ it holds

Answer 11

heat energy (enthalpy)

Question 12

Two units of Enthalpy (heat energy)

Answer 12

joules(J), calories(cal)

Question 13

The first law of Thermodynamics states that

Answer 13

energy cannot be created or destroyed.

Question 14

Heat is it’s own __ and can therefore be written in chemical equations

Answer 14

entity (ie. H2O(l) -> H2O(s) + 6.03 kJ)

Question 14

Entropy is a measure of the

Answer 14

disorder in a system or process

Question 14

Entropy is represented by the symbol

Answer 14

^S (triangle symbol)

Question 15

When ^S for a reaction or process is positive there is __.

Answer 15

increasing disorder in the process

Question 16

When ^S is negative there is __.

Answer 16

decreasing disorder in the process (also known as increasing order)

Question 17

The second law of thermodynamics states that

Answer 17

the entropy (or disorder) of the universe is always increasing.

Question 18

processes which go from fewer molecules to more molecules overall have an increase in __(2)

Answer 18

disorder, or entropy.