*Acid-Base Titrations This site has a variety of interactive acid-base titrations that can be performed.   Strong Acid - Strong Base Weak Acid/Strong Base Strong Acid/Weak Base All Combinations Sketch Graph Choice of Indicators Gas Laws This site provides interactivity that covers several gas laws.   Diffusion of gases: Effect of Temperature and Molar Mass Boyle's Law Model Relationship Between Volume, Pressure and Temperature for a Fixed Mass of Gas Equilibrium The equilibrium between H2 + I2 <==> 2 HI. Adjustments can be made so students can to identify how the concentrations vary. Kinetics The site has a variety of interactive lab simulations that cover every almost every aspect of kinetics.   Gas Kinetics Rate expressions: First Orderl Rate expressions: Second Order Temperature Effects: Kinetics/Collision Theory Temperature Effects: Kinetics/Transition State Theory Temperature Effects: Rate Constant Kinetics & Gas Simulator Great illustration of the movements of molecules under a variety of conditions. Le Chatelier's Principle Model This model demonstrates the attainment of equilibrium in a model chemical reaction. The way in which the position of equilibrium is affected by altering the conditions is summarized by Le Chatelier's principle. Molecules in Motion Temperature, mass, the number of particles, and internal pressure can be manipulated to see the effect on the movement of molecules. *Periodicity These applets provide an excellent look at periodicity of properties amongst the elements.   Periodicity: Atomic & Ionic Radii Periodicity: Physical Properties Principle Species & pH in Acid Base Solutions Pick the volume of a given concentration of an acid and base and it will identify concentrations of each species at the start, before and at equilibrium. Buffers can also be worked with. Stoichiometry One of the first numerical problems encountered in introductory chemistry is that of "limiting reagents". The applet does not approach or solve the problem as it would be done with paper and pencil, on the blackboard, or in the textbook. Rather, it serves as a supplement to such calculations, providing imagery that helps students see beyond a route mathematical procedure. In lecture, the instructor may work through the problem on the blackboard, referring to the applet as a constant visual reminder of what is being calculated and why. Outside lecture, students may use the applet while solving problems, to generate and check intermediate results and help them discover and correct their own mistakes. Variation of Boiling Point with Pressure Compares the varying pressures and initial temperatures of a water vapor pressure curve, the estimated vapor pressure curve using Trouton's rule, and the methane vapor pressure curve.