# 1.1 States of Matter

The three states of matter

Change of State

Types of Matter

Types of reactions

• Combination or synthesis (Example)

• Decomposition​​ (Example)

• Simple replacement (Example)

• Double replacement (Example)

Utilization

• Atom Economy

• Definition: "Measure that accounts for the efficiency of chemical reactions by comparing the amount of reactants with the amount of products."

• Formula:

• Freeze-drying of foods:​ Low temperature and low pressure to sublime water, in order to maintain taste.

• Refrigeration: Energy changes during the evaporation and condensation of a volatile fluid under changing pressure.

# 1.2 Amount of Substance

Relative atomic mass (Ar)

Definition: The weighted average of the atomic masses of its isotopes and their relative abundance, compared to 1/12th of a carbon-12 atom. Unit:

Same concept is applied for Relative Molecular mass

Molecular formula

Definition: "The actual number of of atoms of each element in one compound." (Bylikin, 2014)

Example: Ethane:

Relative amount of substance

• Formula:

Mole (n)

Definition: an SI unit defined as a fixed amount of substance. For instance, a dozen is 12 units of something, the same way a mole is                units of something.

Empirical formula

Definition: "the simplest whole number ratio of atoms of each element in one compound." (Bylikin, 2014)

Example: Ethane:

# 1.3 Stoichiometry

Definitions

• Stoichiometry: the quantitative method of examining the relative amounts of reactant and products.

• Limiting agent: the reactant that will be completely consumed during the reaction.

Yields

• Theoretical yield: the yield that is calculated.

• Experimental yield: the yield that is obtained.

• Difference between yields due to:

• impurities

• change in the conditions of a reaction

• reverse reactions

• side reactions

• loss of product

• Percentage yield:

Note: The concepts of yields are very important for industries. One important example is the Haber-Bosch process (production of ammonia).

Gases

STP (Standard temperature and pressure): 273 K and 100kPa

Molar volume of a gas

• Definition: "the volume of 1 mole of a gas a constant at a given temperature and pressure."

• Assumptions:

• Gases are made from small particles

• Particles move in straight lines and in different directions

• There is no kinetic energy loss

• There is no force of attraction between molecules

• Molar volume of a gas at STP​:

• ​Gas Laws:
• Formula​​:
• Tip: this formula involves the change in temperature, pressure or volume.

Note: Temperature is always in K

• Ideal Gas Equation:
• Formula:

Titration:

• A quantitative and volumetric analysis

• Generally uses indicators

• Example: Acid-Base titrations or potentiometric titrations (not in the core syllabus)

Utilization

Air bags: the use of gas laws to "play"the correlation between pressure, temperature and volume in order to quickly expand the total volume of the air bag in case of an accident.

​​Tip: this formula does not involve the change in temperature, pressure or volume.

Solutions

Concentration:

• Formula: