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

I am going to investigate what effect concentration has on the rate of reaction.

Extracts from this document...


Chemistry Coursework Rate of Reaction Planning Things that affect the rate of reaction are: * Concentration * Temperature * Catalysts * Surface areas I am going to investigate what effect concentration has n the rate of reaction. I hypothesise that as the concentration becomes more diluted, the rate of reaction will increase. This is because when molecules in the reactants are colliding due to kinetic energy they don't always react with molecules in other reactants. When the concentration of the sodium thiosulphate is diluted, there will be more water and this will prevent the hydrochloric acid from reacting with the sodium thiosulphate as quickly. Water doesn't react with acid. The factor I will vary is the concentration of the sodium thiosulphate. This is because I am investigating the concentration so to alter the concentration I need to take out some sodium thiosulphate each time I do the experiment and add water to it each time as well. I am using sodium thiosulphate with a concentration of 0.3 (20ml� of sodium thiosulphate), 0.24 (16ml� of sodium thiosulphate 4ml� of water), 0.18 (12ml� of sodium thiosulphate and 8ml� of water), 0.12 (8ml� of sodium thiosulphate and 12ml� of water) ...read more.


* A piece of paper/card with a thick black X on it - so we know when the reactants have finished reacting. Diagram Method First we collected our equipment and set it up as above. We measured out all our amounts of sodium thiosulphate and put each one in a different test tube. We also measured 10ml� of hydrochloric acid. We took the test tube which had the sodium thiosulphate with 20ml� in. e poured this into the conical flask which was on top of the black X. We then poured in the hydrochloric acid and started to time straight away. We watched the black X and as soon as we could no longer see it we stopped timing. We recorded this time. We poured the solution back into the test tube and then placed the test tube back in the test tube rack. We also rinse out the conical flask. We then took the next measurement of sodium thiosulphate (16ml�) and poured this into the conical flask which had now been placed back on the X. We then measured out another 10ml� of hydrochloric acid but this time we measured 4ml� of water as well. ...read more.


2nd experiment time (secs) 3rd experiment time (secs) Average time (secs) 0.3 25.34 25.33 26.17 25.69 0.24 32.23 33.45 32.86 32.85 0.18 44.57 45.83 43.08 44.49 0.12 83.15 81.89 80.89 81.98 0.06 131.39 132.13 133.16 132.39 Analysis My averages are pretty good, there doesn't appear to be any erroneous data from looking at the results table either. My graph shows that as concentration gets more dilute, the time it takes for the reaction to occur increases. The trend in my data is that the more dilute the concentration gets, it takes even longer for the reaction to finish. e.g. 0.3 = 25.69 0.24 = 32.85 0.18 = 44.49 0.12 = 81.98 0.06 = 132.39 My results back up my prediction. I predicted that as concentration decreased the rate of reaction would increase. Looking at my graph and results table, this is what happened. Evaluation My repeat experiments were pretty close, only usually one or two seconds out from each other. This would mean that my evidence was of good quality. In the future I could do something like using 40ml� of sodium thiosulphate instead of 20ml� to see if the volume I used had anything to do with what results I got. ...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