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

Hydrochloric acid and sodium Thiosulphate Investigation

Extracts from this document...

Introduction

Hydrochloric acid and sodium Thiosulphate Investigation Introduction: for this experiment/investigation I want to find out how long it takes for two different solutions to react togeather, these are; Hydrochloric acid and sodium Thiosulphate. I will change the concentration of the sodium thiosulphate to see whether this affects the rate of the reaction. Other things that may affect the rate of a reaction are temperature, catalysts, size of bits and surface area, but were just testing the concentration area. A reaction goes quicker if the temperature rises. This is because of the increase in kinetic energy, which enables the particles to collide more quickly. A powdered substance reacts more quickly than one with larger bits. This is because the powder has much bigger surface area, so more reacting particles come into contact. Concentration is the number of particles there are in a given volume; this is measured in Molarity. I will use 0.15 M of sodium thiosulphate. For these two chemicals to react (sodium thiosulphate and hydrochloric acid) they will need to create Ions, and these need to collide so the more there are the more chance of them colliding and the quicker the reaction will be. If there's an increase in concentration there will be and increase in Ions and this increases the chance of a successful collision. ...read more.

Middle

AS SOON as you do this start the stopwatch and record how long it takes for the black cross to disappear. Repeat all this two more times so we can be sure the results are accurate. Then do it again changing the concentration of sodium thiosulphate, using the table shown below concentration Volume in 15m of sodium thiosulphate dc. volume of water 0.15 50 0 0.12. 40 10 . 0.9 30 20 0.6 20 30 0.3. 10 40 Prediction: My prediction is that the reaction between sodium thiosulphate and hydrochloric acid will get slower as the sodium thiosulphate is diluted with water. If the concentration of the thiosulphate decreases, the rate of reaction also decreases because there has to be enough of the sodium thiosulphate Ions for the hydrochloric acid to react with. I also think that the concentration is proportional to the rate of reaction so if I doubled the concentration the time in which it takes for the reaction to take place will double too. E.g.- 0.03 may take 1200 seconds so I think that 0.06 would take 600 seconds (just an example) Or concentration x 2 = rate of reaction /2c I also think I will get a graph that looks like this so I think that as the concentration of the reactant increases time will decrease or concentration of reactant decreases with time. ...read more.

Conclusion

But then again this may not have been done correctly as well, there could have been still some solution left in it. Therefore this would have affected the rate of reaction. My results completely support my prediction because I said that that the reaction between sodium thiosulphate and hydrochloric acid will get slower as the sodium thiosulphate is diluted with water. If the concentration of the thiosulphate decreases, the rate of reaction also decreases. When the concentration was only 0.3 it took 1207 seconds and at 0.15 it took 72 seconds, so yes when I increased the amount in which in was diluted by water it did get slower. And my graph cam out as I predicted, I got no strange results. They were pretty good, BUT if I was to this investigation again I would use different measuring cylinders for each measurement I make, I would try to do it all on the same day and at the same temperature because these both could have affected the results I got. I would also consider doing the experiment more than 3 times for each solution, just to check and I would maybe go higher than the concentration of 0.15, so I can see how quickly it is possible for it to take. Then I could fully test the theory of if I double the concentration, will the rate of the reaction always be half? ...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
  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work