Liquids and Solids Overview

These flashcards cover key concepts related to intermolecular forces, properties of liquids and solids, phase changes, and related calculations for upcoming exams.

What do intermolecular forces (IMF) represent in condensed phases?

IMFs are attractive forces that hold particles together in liquids and solids.

What is the relationship between the strength of intermolecular forces and physical properties of liquids such as viscosity and surface tension?

Stronger intermolecular forces result in higher viscosity and surface tension.

What is the Clausius-Clapeyron equation used for?

It relates vapor pressure and temperature to calculate enthalpy of vaporization.

What are the strongest intermolecular forces listed in order?

Ion-ion, Ion-Dipole, Dipole-Dipole, Hydrogen bonding, Dispersion Forces.

What characterizes a crystalline solid?

It possesses rigid and long-range order with atoms in specific positions.

How do you calculate the density of a crystalline solid?

Density (d) = Mass (m) / Volume (V).

What is the triple point in a phase diagram?

The unique combination of pressure and temperature where all three phases (solid, liquid, gas) exist in equilibrium.

What is hydrogen bonding and how does it differ from a regular bond?

Hydrogen bonding is a strong type of dipole-dipole interaction, not a formal bond, occurring with H bonded to electronegative atoms.

Which phase change occurs when a solid turns directly into a gas?

Sublimation.

What happens to vapor pressure when the temperature increases?

The vapor pressure typically increases.

What do intermolecular forces (IMF) represent in condensed phases?

IMFs are attractive forces that hold particles together in liquids and solids.

What is the relationship between the strength of intermolecular forces and physical properties of liquids such as viscosity and surface tension?

Stronger intermolecular forces result in higher viscosity and surface tension.

What is the Clausius-Clapeyron equation used for?

It relates vapor pressure and temperature to calculate enthalpy of vaporization.

What are the strongest intermolecular forces listed in order?

Ion-ion, Ion-Dipole, Dipole-Dipole, Hydrogen bonding, Dispersion Forces.

What characterizes a crystalline solid?

It possesses rigid and long-range order with atoms in specific positions.

How do you calculate the density of a crystalline solid?

Density d = \frac{m}{V}, where m is the mass and V is the volume of the unit cell.

What is the triple point in a phase diagram?

The unique combination of pressure and temperature where all three phases (solid, liquid, gas) exist in equilibrium.

What is hydrogen bonding and how does it differ from a regular bond?

Hydrogen bonding is a strong type of dipole-dipole interaction, not a formal bond, occurring with H bonded to electronegative atoms.

Which phase change occurs when a solid turns directly into a gas?

Sublimation.

What happens to vapor pressure when the temperature increases?

The vapor pressure typically increases.

What are Dispersion (London) forces?

Temporary dipole-induced dipole attractions caused by the constant motion of electrons; they are present in all molecules.

Define Polarizability.

The ease with which the electron distribution in the atom or molecule can be distorted by an external electric field.

What is the two-point form of the Clausius-Clapeyron equation?

\ln\left(\frac{P2}{P1}\right) = \frac{\Delta H{vap}}{R} \left( \frac{1}{T1} - \frac{1}{T_2} \right)

What is a Unit Cell?

The smallest repeating basic structural unit of a crystalline solid.

How many atoms are in a Face-Centered Cubic (FCC) unit cell, and what is the coordination number?

There are 4 atoms per unit cell, and the coordination number is 12.

What is the Critical Point on a phase diagram?

The point defined by the critical temperature (Tc) and critical pressure (Pc), above which the liquid and gas phases are indistinguishable (Supercritical Fluid).

What is the boiling point of a liquid?

The temperature at which the vapor pressure of a liquid is equal to the external atmospheric pressure.

What are Cohesive vs. Adhesive forces?

Cohesive forces are intermolecular attractions between like molecules, while adhesive forces are attractions between different types of molecules.

What is Molar Heat of Fusion (\Delta H_{fus})?

The energy required to melt one mole of a solid substance at its melting point.

What defines a Covalent Network Solid?

A solid where atoms are held together in an extensive three-dimensional network of covalent bonds, resulting in high melting points and hardness (e.g., Diamond or SiO2).