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.
Conversion Between Mass and Moles of an Element (Screencast)
Atomic weights are used to convert the mass of a sample into the number of moles of the element in the sample and vice versa. Four examples are provided for practice.
Determining Empirical and Molecular Formulas (Screencast)
Learners follow a four-step process to determine the empirical formula of a compound from the masses of its constituent elements. The molecular formula is determined in a fifth step using the molecular weight of the compound.
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.
In this well-illustrated object, learners examine the structures and properties of the four types of solids: molecular, metallic, ionic, and covalent network. Five interactive questions are provided.
Common Types of Oxidation-Reduction Reactions (Screencast)
Learners identify combination, decomposition, displacement, and combustion types of redox reactions. They also watch a video clip that demonstrates the reaction of sodium and water.
In this animated and interactive object, learners examine the inverse proportionality of wavelength and frequency and their relationship to the speed of light.
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.
In this interactive object, learners determine the limiting reagent and the excess reagent in chemical reactions. Learners test their knowledge by solving three problems.
The Effect of Temperature on the Vapor Pressure of a Liquid
Learners examine how vapor pressure is calculated. The vapor pressure of a liquid increases with increasing temperature. If the heat of vaporization and the vapor pressure at one temperature are known, the vapor pressure at a second temperature can be calculated.
In this animated activity, learners examine what gases are composed of and how their particles interact. They also consider several assumptions that form the basis for the Kinetic Theory of Gases.
In this interactive and animated object, students distribute the valence electrons in simple covalent molecules with one central atom. Six rules are followed to show the bonding and nonbonding electrons in Lewis dot structures. The process is well illustrated with eight worked examples and two interactive practice problems.
Learners view movie clips to determine the solubility of two ionic compounds. They also examine a solubility chart and predict the solubility of compounds.
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.