Essential Chemistry Concepts: Thermochemistry, Solutions, and Reactions

Essential Chemistry Concepts

1. Thermochemistry

Thermochemistry is the branch of chemistry that studies the changes in temperature that occur during a chemical reaction.

2. Heat of Formation

Heat of formation is the energy inherent in elements, which is transformed when it receives energy from an external source.

3. Heat of Reaction

Heat of reaction is the energy absorbed or released during a chemical reaction.

4. First Law of Thermodynamics

The first law of thermodynamics, also known as the law of conservation of energy, states that energy cannot be created or destroyed, only transformed.

5. What is a Solution?

A solution is a mixture of two or more components with a uniform consistency.

6. Types of Solutions

• Homogeneous
• Heterogeneous
• Simple Solution
• Colloid
• Suspension

7. Physical and Chemical Units

• Physical Units: kilograms, meters, seconds, newton, etc.
• Chemical Units: moles, atomic mass units (amu), gram moles.

8. Boiling Point of Water

100 °C

9. Freezing Point of Water

0 °C

10. Physical and Chemical Properties of Matter

• Physical Properties: Properties of matter where the structure does not change.
• Chemical Properties: Properties of matter where the structure changes.

11. What is an Acid?

An acid is a substance with a pH less than 7.

12. Characteristics of Acids

• Sour taste
• Conducts an electric current
• Reacts with bases to produce salts and water

13. What is a Base?

A base is a substance with a pH greater than 7.

14. Characteristics of Bases

• Bitter taste
• Reacts with acids to produce salts and water
• Soapy feel

15. Is Water Acidic, Basic, or Neutral?

Water is neutral because its pH is 7.

16. Define Neutralization

Neutralization occurs when an acid and a base combine, their individual properties are neutralized, producing compounds such as salts and water.

17. Difference Between an Acid and a Base

The difference is their pH value.

18. What is a Chemical Bond?

A chemical bond is the force of attraction between two atoms.

19. What is a Covalent Bond?

A covalent bond is a bond where electrons are shared.

20. What is an Electrovalent Bond?

An electrovalent bond is a bond where atoms are joined by their different charges.

21. What is an Ionic Bond?

An ionic bond is a bond where atoms are joined by their different charges.

22. Define Coordinate Covalent Bond

A coordinate covalent bond is a covalent bond where the two shared electrons are donated by the same atom.

23. Define Metallic Bond

A metallic bond is a bond between two metals.

24. Define Hydrogen Bond

A hydrogen bond occurs when a hydrogen atom lies between two atoms of higher electronegativity.

25. What is Oxidation?

Oxidation is when an atom loses one or more electrons.

26. What is Reduction?

Reduction is when an atom gains one or more electrons.

27. Determine the Oxidation Number

The oxidation number is the number of electrons revolving in the last layer of an atom.

28. Behavior of Gases

The molecules are of equal size and mass, its density is low and its molecular attraction is minimal, the volume occupied in a container is minimal.