DrDAQ

Data logger, oscilloscope, signal generator and more!

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.

From just £89.00

More

Monitoring the rate of reaction between two liquids

educational data acquisitionIntroduction

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.

Equipment required

  • DrDAQ data logger connected to a PC
  • Home-made light sensor (described below)
  • Suitable chemicals (e.g. 1M hydrochloric acid, 40 g/l sodium thiosulphate; or starch solution with iodine indicator with amylase; or milk with trypsin; or neutralisation of alkali using phenolphthalein)

The sensor components

  • Block of wood about 10 cm x 5 cm x 5 cm
  • LDR (Maplin part number HB10L)
  • LED (Maplin part number NP03D)
  • 2 resistors (330 ohm and 3.9k ohm)
  • 9 volt battery
  • Sundries (wire, solder, sticky tape)

Sensor construction

The block of wood is drilled to accommodate the electronics as shown below:

DrDAQ rate of reaction setup

Figure 1: diagram showing the experiment set up

The components are best held in place using the glue from a hot glue gun. The circuit is connected as shown below:

DrDAQ rate of reaction circuit

Figure 2: diagram showing the circuit

Carrying out the experiment

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.

Questions and discussion of results

  1. Why is the gradient of the graph initially quite steep but becomes less steep as time progresses?
  2. What shape does the graph take if the chemicals are warmer?
  3. What shape does the graph take if the chemicals are diluted?

Further study

  • What would happen to the shape of the graph if the reactants were warmer (or cooler)?
  • What would happen to the shape of the graph if the reactants were diluted (or concentrated)?
  • If the reaction employs a catalyst or enzyme, what is the ideal temperature of the chemistry?
  • What effect does pH have on enzymes?

Testimonials

  • I have been using my 4224 PicoScope for years. I travel abroad so this has been ideal due to its physical size. Storage of waveforms on my Laptop is very easy allowing me to quickly email waveforms to my Colleagues.

    Andrew
  • Not many USB scopes works on Win & Mac & Linux too, so that proves me that guys from Pico really cares about us, customers. This made my decision much easier when I was looking to buy an USB scope.

    Raul Trifan
  • We have been using Picoscope 6404D for quite some time, and are amazed by its accuracy and powerful emulations while working with numerous signal evaluations.

    J Mohanty
  • PicoLog TC-08: This is a very nice unit that works consistently and reliably.

    Jeff Hulett
  • It is a great scope. I had a weird problem - it did not work on one of my PC’s. Customer service gave me first class service. If I could give 6 stars for customer service - I would do so.

    Niels Larsen
  • Perfect Partner for Development of Encoder controlled Stepper Motor Actuators. Since the included software is really stable, this type of device is a great tool for great tasks!

    Helmut Schoettner
  • A superb piece of equipment worth its weight in gold

    Nigel Clinch
  • So simple to use & beats any other I have ever used hands down.

    John D Samsing
  • Great functionality in a compact size. I really like moving the mouse pointer to a position and having the Time and Voltage display the values at that point. Calibration equipment is a breeze with that feature.

    Don Horein

PC oscilloscope and data logger products

Tel: +1 800 591 2796 (Toll Free)