• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

To investigate factors affecting the rate of electrolysis when electrolysing a potassium nitrate solution.

Extracts from this document...


Chemistry Investigation- Electrolysis Aim To investigate factors affecting the rate of electrolysis when electrolysing a potassium nitrate solution. Theory: When electrolysing a potassium nitrate solution, there are four ions present: 1. H+ From water (H- H+ + OH- ) 2. OH- From water (H2O H+ + OH- ) 3. K+ From Potassium Nitrate 4. OH3- From Potassium Nitrate H+ and K+ compete for electrons at the cathode. K+ is the more stable of the two, so therefore it is H+ that reacts: 2H+ (aq) + 2e- --> H2(g) OH- and NO3- compete to lose electrons at the anode. NO3- is more stable, therefore OH- will react. 0H- (aq) --> 0H- (aq) + e- Uncharged OH is unstable so it reacts: 40H- (aq) --> 2 H2O(1) + O2 (g) When electrons are released by OH- ions when they react are pushed round the circuit by the power supply into the gaps left by the electrons reacting with the H+ Ions: Therefore the rate of electrons flowing round the circuit is dictated by how fast the reactions are occurring. This means that current can be used as a measure of the rate of reaction Variables There are several variables I could change, these are: * Voltage. ...read more.


For my second variable- potassium nitrate concentration, I can make this prediction based on my theory above. This variable should have an effect on the ROR because with less potassium nitrate in the solution, the electrons are less likely to cause a reaction, so the rate of reaction will be slower, and this is basically the collision theory. So in summary I predict that the greater the concentration of Potassium Nitrate, the greater the ROR. I predict to see two graphs similar to these. Equipment * Potassium Nitrate * Water * Measuring cylinder * Power supply * Carbon electrodes * Ammeter * Beaker Method I will set up the equipment up as shown below: I will then turn the power supply and take readings with the ammeter for the different voltages in my range. I will do the same for my second variable, except I will vary the concentration of the potassium nitrate each time. I will then record my results: Results 1st Variable; 100ml 100% concentration: Volts (V) Current (amps) (repeat 1) Current (amps) (repeat 2) 2 0 0 4 0.2 0.4 6 1.2 1.4 8 2.0 2.4 10 3.4 3.7 12 4.6 4.8 2nd Variable; 8V 100ml potassium Nitrate solution: Potassium Nitrate Concentration (% out of 100ml) Current (amps) (repeat 1) Current (amps) (repeat 2) ...read more.


If I was going to continue with this investigation I would go on to see how Temperature affects the reaction, I would do this by heating the reaction and measuring the temperature and current. I could also change this experiment by recording a different variable. I could measure the gas given off by the reaction, like below: My results are consistent when drawn up on a graph; generally they show consistency in my results, which leads me to believe that my results are accurate. I feel most of my results are accurate, although there are a few anomalies, these could be due to any number of reasons, I have listed some below. * The measuring equipment I used may not have been as precise as more expensive equipment used in industry. This may add to the inconsistency of my results. * My measuring out of solutions of potassium nitrate and water may not have been 100% accurate. * Experimental error- I may have made a small mistake in reading the ammeter or made another small mistake, which could affect my results. * Temperature - the potassium nitrate may not have been at a constant temperature, if the temperature rose, then my results would have been affected. My results support my conclusion, so I can say they are reliable. Look at my graph, it shows my results support my conclusion. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Patterns of Behaviour section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Patterns of Behaviour essays

  1. An Investigation into the effect of concetration on the Rate of Reaction Between Potassium ...

    A stop clock was taken and as the two solutions were poured in to the beaker the stop clock was started. A person observed above the beaker until the two solutions had reacted and the cross had disappeared and then the stop clock was stopped.

  2. Investigation into the factors affecting the rate of infiltration of soils with varying agricultural ...

    This should prevent the risk of poisoning or serious injury from livestock/machinery. It is also necessary to inform a family member/friend on the location and estimate time to complete the fieldwork. A mobile phone is a useful item but must not be relied upon, as reception can be poor.

  1. Factors Affecting Enzyme Activity

    I will then use the 5cm3 syringe to measure out 5cm3 of hydrogen peroxide. I will place the syringe into the bung and ensure that all my apparatus is air tight. I will then quickly inject all of the hydrogen peroxide into the boiling tube whilst simultaneously starting the stop clock.

  2. Investigation Into the Factors Affecting Rate of Reaction

    I will also make sure I do not inhale the solution as this may irritate my body and finally I will make sure I report and spills to my teacher immediately. Apparatus Hydrochloric Acid- The amount will change during my experiment Sodium Thiosulphate- This will be kept the same during

  1. How Hitler came to power

    I will repeat each temperature three times to ensure accurate results. I will take the average of the three results to produce overall more accurate results for each temperature. Main Results Temperature of water and enzyme ( C) Reaction Time (seconds)

  2. To investigate the factors affecting the rate of reaction.

    If the particles have enough energy between them there is a successful collision resulting in a reaction. If the particles do not have enough kinetic energy and therefore not enough energy they bounce apart and no reaction take place. When various reactions take place, different minimum energy levels are needed to make a successful collision resulting in a reaction.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work