Chapter 1: Matter - Properties, Classification, and Phase Changes

Flashcards covering matter classification, physical/chemical properties, kinetic/potential energy, phase changes, latent heat, and phase diagrams from Chapter 1 notes.

What is the scientific definition of matter?

Matter is anything that has mass and occupies space (volume). Energies such as light, sound, and heat are not matter.

How do extensive properties differ from intensive properties?

Extensive properties depend on the amount of material present (such as mass, volume, and total heat energy), whereas intensive properties do not depend on the amount of material (such as density, boiling point, freezing point, and temperature).

What distinguishes a physical change from a chemical change?

In a physical change, no new substance is formed and intermolecular distances change while particle identity remains identical. In a chemical change, original bonds break and new bonds form to create a new substance.

What is kinetic energy, and what is its mathematical formula?

Kinetic energy is the energy associated with the motion (speed) of molecules, calculated using the formula $KE = \frac{1}{2}mv^2$.

What three types of motion can a particle (atom or molecule) undergo?

Particles can undergo vibration (back and forth motion in solids, liquids, and gases), rotation (movement about an axis in liquids and gases), and translation (movement from place to place in gases).

How is temperature defined at the particle level?

Temperature is the average kinetic energy (speed) of all particles in a sample.

What is potential energy at the particle level?

Potential energy is stored energy associated with the spacing or distance between neighbouring particles.

What is plasma, and under what conditions is it created?

Plasma is the 4th state of matter, a gas-like state in which electrons pop off gaseous atoms to produce a mixture of free electrons and cations ($e^- + A^+$). It requires very high temperatures, very low pressures, or both.

Why does temperature remain constant during a phase change such as melting or boiling?

Energy added during a phase change is used exclusively to break attractive forces between particles and increase spacing (increasing potential energy), so kinetic energy (particle speed) and temperature remain unchanged.

What is the difference between latent heat of fusion and latent heat of vaporization?

Latent heat of fusion is the energy required to break attractive forces in a solid during melting at its melting point, whereas latent heat of vaporization is the energy required to break attractive forces in a liquid during boiling at its boiling point.

Why is a substance's heat of vaporization significantly greater than its heat of fusion?

Vaporization requires overcoming nearly all intermolecular forces to achieve complete particle separation into a gas, whereas fusion only requires breaking rigid crystal arrangements to allow particles to slide past one another.

Why is the heat of combustion higher than the heat of vaporization for a substance?

Combustion involves breaking and reforming strong chemical bonds to create new chemical products (releasing high energy), whereas vaporization is merely a physical change requiring energy to overcome weaker intermolecular forces.

How is matter classified according to physical separation and chemical decomposition?

Matter is physically separated into mixtures or pure substances. Pure substances are chemically decomposed into compounds or elements. Mixtures are divided into homogeneous mixtures (solutions) and heterogeneous mixtures (colloids and suspensions).

What are the particle size ranges for solutions, colloids, and suspensions?

Solute particles in a solution are less than $1\,nm$, in a colloid they range from $1\,nm$ to $1000\,nm$, and in a suspension they are greater than $1000\,nm$ (or $1\,\mu m$).

What is the Tyndall effect?

The Tyndall effect is the scattering of a beam of light by suspended solute particles in a medium, making the path of light visible in colloids and suspensions, but not in solutions.

What is the structural difference between organic and inorganic compounds?

Organic compounds contain carbon atoms bonded to hydrogen atoms, whereas inorganic compounds do not contain carbon-hydrogen bonds.

What distinguishes an ionic compound from a molecular compound?

An ionic compound forms between a metal and a non-metal through electron transfer (creating cations and anions), whereas a molecular compound forms between non-metals sharing electrons.

What is a supercritical fluid (SCF)?

A supercritical fluid is a state of matter existing beyond the critical point (high temperature and high pressure) where liquid and gas phase boundaries disappear, allowing it to diffuse through solids like a gas and dissolve substances like a liquid.

What is the triple point on a phase diagram?

The triple point is the unique temperature and pressure condition at which solid, liquid, and gas phases coexist simultaneously in equilibrium.

What parameters define standard temperature and pressure (STP)?

STP stands for Standard Temperature ($0^\circ\text{C}$) and Standard Pressure ($1\,\text{atm}$).