Thermochemistry & Reaction Rates
Measuring enthalpy changes (heat of solution) and tracking reaction rate via the "disappearing cross" method (sodium thiosulphate and acid).
STATUS
This lab is in development.
When complete, this will be a guided, step-by-step 3D simulation of the real chemistry practical. For now, you can read exactly what the simulation will cover below.
What you’ll do
The guided simulation will walk you through these steps in order.
- 01Part A - Heat of solution: Record the initial temperature of 100 cm³ of distilled water in a polystyrene cup.
- 02Weigh a measured mass of the solute (e.g. anhydrous sodium chloride or potassium nitrate); add it to the water and stir.
- 03Record the maximum or minimum temperature reached; calculate ΔT and then ΔH using Q = mcΔT.
- 04Part B - Disappearing cross: Draw a bold X on paper; place a conical flask over it.
- 05Measure 50 cm³ of sodium thiosulphate solution into the flask; add a measured volume of dilute HCl and immediately start the stopwatch.
- 06Look down through the flask; stop the timer when the cross is no longer visible through the cloudy precipitate.
- 07Repeat at different concentrations (or temperatures) and plot rate (1/time) against the variable to show the relationship.