Study sheet: Fundamental Chemistry and Quantities

📋 Course Outline

1. Matter and Chemical Science
2. States and Changes of Matter
3. Chemical Entities and the Mole
4. Quantitative Descriptions of Matter

📖 1. Matter and Chemical Science

🔑 Key Concepts & Definitions

• Chemistry : the science dedicated to studying matter and its transformations
• Matter : anything that has physical reality and is composed of microscopic entities such as atoms and molecules

💡 Memory Hook

Matter undergoes transformations, so chemistry studies both matter and its changes.

📖 2. States and Changes of Matter

🔑 Key Concepts & Definitions

• Chemical change : modifies the nature of a substance through a chemical reaction

📝 Essential Points

📌 The three states of matter are solid, liquid, and gaseous states, and temperature and pressure influence which state matter adopts.

• A solid has a defined shape and volume and is ordered and rigid.

• A liquid has a volume, takes the shape of its container, is disordered, and is incompressible.

• A gas has neither a defined shape nor a defined volume, occupies all available space, and is disordered.

• Physical changes of state include:

  • fusion: solid to liquid
  • solidification: liquid to solid
  • sublimation: solid to gas
  • condensation: gas to liquid
  • evaporation: liquid to gas

💡 Memory Hook

A solid keeps its shape, a liquid keeps its volume, and a gas keeps neither.

📖 3. Chemical Entities and the Mole

🔑 Key Concepts & Definitions

• Mole : The mole is an amount of substance corresponding to 6.023 × 10^23 entities, with one mole of carbon-12 having a mass of 12 g.
• Atomic mass unit : one twelfth of the mass of a carbon-12 atom and equals 1.6 × 10^-24 g or 1.6 × 10^-27 kg

📝 Essential Points

📌 An atom is described as the smallest particle of matter, whereas a molecule is an association of at least two atoms, such as O2 or NaCl.

📐 Formula — The number of particles is related to the amount of substance by $N = n \times N_A$, where N is the number of particles, n is the amount of substance, and $N_A = 6.023 \times 10^{23}$ entities per mole.

📐 Formula — The amount of substance is calculated from mass and molar mass using $n = \frac{m}{M}$, where M is the molar mass expressed in g/mol or kg/mol.

💡 Memory Hook

Particle count → amount of substance → mass through N, n, and M.

📖 4. Quantitative Descriptions of Matter

🔑 Key Concepts & Definitions

• Molar concentration : the number of moles of solute per litre of solution
• Mass concentration : the mass of solute relative to the volume of solution

📝 Essential Points

📐 Formula — Molar concentration is calculated by $C_H = \frac{n}{V}$ and is expressed in mol/L.

📐 Formula — Mass concentration is calculated by $C = \frac{m}{V}$ and is expressed in g/L.

💡 Memory Hook

Molar concentration counts moles per volume, whereas mass concentration measures mass per volume.

📊 Synthesis Tables

States of Matter

State	Shape	Volume	Other properties
Solid	Defined	Defined	Ordered and rigid
Liquid	Container shape	Defined	Disordered and incompressible
Gas	Not defined	Not defined	Occupies all available space; disordered