DrDAQ is a versatile instrument that connects to the USB port of any PC. Using the supplied PicoScope software it can be used as an oscilloscope, spectrum analyzer and signal generator.
This experiment investigates the factors which affect the rate of reaction between two chemicals which form an opaque product (often as a suspension). It should fit in with a key stage 4 scheme of work for materials and their properties — rates of reaction.
The block of wood is drilled to accommodate the electronics as shown below:
The components are best held in place using the glue from a hot glue gun. The circuit is connected as shown below:
The home made sensor is set up and connected to DrDAQ’s voltage terminals. PicoLog is set to measure voltage and display a graph of the results. A time period of 120 seconds is found to be most suited to this type of experiment and the data-logger is allowed to sample results every second. Graph axes are set to automatic.
The test-tube has 5 ml of reactant added (for example hydrochloric acid). Recording is started and 5 ml of the second reactant is added to the test-tube (for example sodium thiosulphate). The reaction is allowed to proceed.