Boiling Point of a Liquid
By Debbie McClinton, Dr. Miriam Douglass, Dr. Martin McClinton
Learners examine how the boiling point increases with increasing pressure. An example from industry is given.
Shapes of Simple Molecules - Part 2
By Dr. Miriam Douglass, Dr. Martin McClinton
Learners examine how five or six groups of electrons around a central atom cause the shape of the molecule to be trigonal bipyramidal, seesaw, T-shaped, linear, octahedral, square pyramidal, or square planar. Seven examples and three interactive questions are provided in this animated activity.
Absolute Zero Temperature
Learners view illustrations showing the direct dependence of the volume of a gas on temperature and consider the relationship between the Kelvin and Celsius temperature scales.
Moles
By Jill Larson
In this animated object, students are introduced to moles as a measurement.
Vapor Pressure
Vapor pressure is the pressure exerted by molecules in the gas phase in equilibrium with a liquid or a solid. Two examples are used to illustrate vapor pressure: the drying of clothes and the evaporation of ice.
Real Gases
In this animated activity, learners compare the van der Waals equation with the Ideal Gas Law.
Oxidation Numbers
Learners assign oxidation numbers to atoms in neutral compounds and in polyatomic ions. Six examples are worked through in detail, and three problems are provided.
Double Replacement Reactions
In this interactive object, learners identify charges on ions, write new formulas based on charge, and balance equations using coefficients.
Oxidation States of Ions
Learners examine the periodic table to identify metallic elements that have either fixed or variable oxidation states.
The Mole and Avogadro's Number
Learners examine how chemists use moles to "count" atoms by weight. Examples are given.
Calculation of Atomic Weight from Isotopic Composition
Learners examine the method for calculating the atomic weight of copper from the natural percent composition of each of its two isotopes.
Phase Diagrams
Learners examine phase diagrams that show the phases of solid, liquid, and gas as well as the triple point and critical point.
Pressure and Boyle's Law
Students examine standard pressure in this interactive object.
Melting Point and Freezing Point
Learners observe that the melting of a solid and the freezing of its liquid occur at the same temperature. The melting point is an intrinsic property and is used to identify a substance.
Covalent Bonds
In this animated object, students examine what happens when electrons share molecules.
Gas Volume vs. Temperature (Charles's Law)
In this animated object, learners examine how gas volume varies directly with absolute temperature (K at constant pressure). An example of a sample of gas at two conditions of volume and temperature is used to illustrate the law.
Acids & Bases
Students read different definitions of "acids" and "bases." In an interactive exercise, they identify if a substance is an acid or a base.
Energy in Chemical Reactions
By Dr. Miriam Douglass
In this animated and interactive object, learners examine kinetic and potential energy as well as the first law of thermodynamics and the flow of energy between a system and its surroundings. Students also answer questions about exothermic and endothermic reactions
Standard Molar Volume
Learners observe that the volume of one mole of any gas is 22.4 L at standard temperature and pressure. An illustration shows that only the mass of the molar volume differs with the identity of the gas.
A Biological Example of Water Solubility
In this animated object, students examine the role that the solubility of water plays in various biological functions.
Phase Transitions
Learners examine how melting, vaporization, and sublimation require energy input while freezing and condensation release energy.
Macroscale vs. Nanoscale
By Karen Nordell
In this colorful, interactive object, learners examine how materials on the nanoscale compare with those on the macroscale. The focus is on the difference between macroscale and nanoscale gold in both color and melting point.
Balancing Oxidation-Reduction Equations
In this animated activity, learners examine the terms "half-reaction," "oxidizing agent," and "reducing agent" and follow five interactive examples to balance equations for oxidation-reduction reactions. Three problems are provided as a self-check.
Heat of Fusion and Heat of Vaporization
Learners examine graphs and read that the heat of fusion is the heat energy absorbed by one mole of solid as it is converted to liquid, while the heat of vaporization is the heat energy absorbed by one mole of liquid as it is converted to gas.
Atomic Weight
Learners read the definition of atomic weight and obtain the weights of elements by viewing the Periodic Table and charts that list atomic weights by name or symbol.