Chemical Reactions & Thermochemistry

Question 1

Combination/Synthesis

Answer 1

Formation of a compound from the union of its elements

Zn + S -> ZnS

Question 2

Decomposition/Analysis

Answer 2

The breakdown of a compound to release its components as individual elements or other compounds
2H2O -> 2H2 + O2

Question 3

Single Replacement

Answer 3

One substance replaces/displaces another

Fe + CuSO4 -> FeSO4 + Cu

Question 4

Double Replacement

Answer 4

Exchange of partners to form new compounds

AgNO3 + NaCl -> AgCl + NaNO3

Question 5

Heat of Formation

Answer 5

The quantity of heat either given off or absorbed in the formation of 1 mole of a substance from its elements

Question 6

Neutralization Reaction

Answer 6

The union of the hydrogen ion of an acid & the hydroxyl ion of a base to form water

Question 7

Hydrolysis Reaction

Answer 7

Salt & water react to form an acid & a base

Opposite of neutralization reaction

Question 8

Entropy

Answer 8

The measure of the randomness or disorder that exists in a system

Question 9

Enthalpy

Answer 9

The heat content of a chemical system

Question 10

Standard State

Answer 10

25 Celsius & 1 atm for reporting heat data

Question 11

Standard Enthalpy of Formation

Answer 11

The change in enthalpy that accompanies the formation of 1 mole of a compound from its elements with all substances in their standard states at 25 C

Question 12

Molar Heat of Formation

Answer 12

25 C

Question 13

Heat of Combustion

Answer 13

The heat released by the complete combustion of 1 mole of a substance

Question 14

Hess’s Law of Heat of Summation

Answer 14

If a series of reactions are added together, the enthalpy change for the total reaction is the sum of the enthalpy changes for the individual steps

Question 15

First Law of Thermodynamics

Answer 15

Total energy of the universe is constant & cannot be created or destroyed