A Chemistry Guide

A set of flashcards covering key vocabulary and concepts related to properties of substances and mixtures in chemistry.

London Dispersion Forces

The sole force in nonpolar substances; caused by temporary dipoles due to random motion of electrons, inducing dipoles in neighboring molecules.

Dipole-Dipole Forces

Intermolecular forces between two polar molecules, increasing in strength with greater polarity.

Ion-Dipole Forces

A type of interaction between an ion and a polar molecule, which is usually stronger than dipole-dipole forces.

Hydrogen Bonding

A strong form of dipole-dipole interaction where a partially positive hydrogen atom is attracted to a partially negative nitrogen, oxygen, or fluorine atom.

Ideal Gas Law

The equation PV = nRT relates the pressure, volume, moles, and absolute temperature of an ideal gas.

Dalton's Law of Partial Pressures

States that the total pressure is the sum of the partial pressures of individual gases.

Kinetic Molecular Theory (KMT)

A theory that describes the behavior of ideal gases in terms of particle motion and collisions.

Molarity

A common unit of concentration, calculated as moles of solute per liter of solution (M = moles/L).

Chromatography

A separation technique that separates components of mixtures based on differences in intermolecular forces.

Beer-Lambert Law

Describes the relationship between absorbance and concentration, indicating that absorbance increases with concentration.

What are the primary types of chromatography and their general separation principle?

Chromatography techniques like Gas Chromatography (GC), Liquid Chromatography (LC), and Thin-Layer Chromatography (TLC) separate components of a mixture based on their differential interaction and distribution between a stationary phase and a mobile phase, often governed by intermolecular forces.

Explain the role of the stationary phase in chromatographic separation.

The stationary phase is the immobile component in chromatography. Analytes in the mobile phase interact differently with it (e.g., through adsorption, partition, or size exclusion), leading to varied retention times and thus separation based on their specific physical and chemical properties and intermolecular forces.

How do you interpret a Maxwell-Boltzmann distribution curve?

A Maxwell-Boltzmann curve displays the distribution of kinetic energies (or molecular speeds) for gas particles at a specific temperature.

• X-axis: Kinetic energy or molecular speed.

• Y-axis: Fraction of molecules with that energy/speed.

• Interpretation: The peak represents the most probable energy/speed. Higher temperatures broaden the curve and shift the peak to the right, indicating a greater fraction of molecules possessing higher kinetic energies.The distribution illustrates how gas particles of varying kinetic energies are present at a given temperature, with the area under the curve representing the total number of particles.