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

How concentration affects rate of reaction

Extracts from this document...

Introduction

Chemistry IGCSE Coursework V�ctor Toledo Science 10A How concentration affects rate of reaction AIM: We wanted to see if changing the concentration of one of the reactants also changed the rate of reaction by changing the ratio of acid to the other reactant. To test this we used calcium carbonate and hydrochloric acid: PLAN: We were going to calculate how concentration affected reaction rate by reacting the calcium carbonate and acid in a conical flask and then collecting the carbon dioxide that would come out in a measuring cylinder filled up to the top. Then we would record how much gas was collected during a minute and repeat these steps with a different concentration of the acid. ...read more.

Middle

4. Get hold of the stopwatch and be prepared. Tell somebody to hold the tube where the entrance to the cylinder is because it might pop out because of the gas' force. Add the two reactants into the conical flask and quickly put the stopper. Start timing immediately. 5. Let 1 minute pass and record the volume of gas in the cylinder. 6. Repeat steps 2-5 but changing in step 3 the concentration of acid by diluting it with water: 20:5, 10:15, etc. VARIABLES Things that were different - Concentration of acid: This was the aim of the experiment, changing concentration to see if rate of reaction also changed. Things that were kept the same - Shape of flask: Depending on the shape of the container, particles would collide more/less often, so results would be inaccurate. ...read more.

Conclusion

Therefore, when concentration is high, reaction rate increases; when it is low, rate of reaction increases. EVALUATION: The reason why varying concentration affects reaction rate is because of the collision theory. This states that the reactant particles collide together and form the chemical reaction. If concentration is high, there are more particles in the same volume so collisions occur more often. There was an anomalous result in our experiment. In the trial for 1.2 moles of concentration there was a peak and instead of 84 it should have been in between 40 and 61. The problem might have been that the mixture was mixed too much, there was too much of calcium carbonate, the stopper was put much faster than others. We could have improved timing, more accurate measurements and making sure that no gas escapes before getting to the cylinder. ?? ?? ?? ?? ...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 Classics section.

Found what you're looking for?

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

Here's what a teacher thought of this essay


This report includes the basic elements for a sound laboratory report. It is significantly limited by the small amount of data collected and the basic and brief evaluation of that data. What was written was done well.

Marked by teacher Cornelia Bruce 17/04/2013

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 Classics essays

  1. Marked by a teacher

    Rate of Reaction Chemistry Coursework

    4 star(s)

    we use .Scales- We use this to measure the amount of magnesium we use .Water bath- We use to adjust the temperature of the hydrochloric acid .Hydrochloric acid- We use this to get a reaction along with magnesium .Magnesium Ribbons- We use this to get a reaction along with hydrochloric

  2. Marked by a teacher

    Chemistry rate of reaction coursework

    3 star(s)

    25cm3 0cm3 5cm3 T1 16.31 T2 16.55 T3 16.43 20cm3 5cm3 5cm3 T1 20.59 T2 20.54 T3 18.50 15cm3 10cm3 5cm3 T1 27.45 T2 26.66 T3 27.13 10cm3 15cm3 5cm3 T1 45.07 (outlier) T2 37.04 T3 36.12 5cm3 20cm3 5cm3 T1 82 T2 78 T3 73 Explanation of outlier: I

  1. Marked by a teacher

    How does varying the concentration in a reaction affect the rate of reaction?

    3 star(s)

    4.09 4.16 0.240 2.50 3.93 2.82 3.53 3.43 0.292 3.00 2.28 2.28 2.50 2.35 0.426 4.00 1.65 1.68 1.87 1.73 0.578 Conclusion Graph 1 shows that as the concentration of the hydrochloric acid increases, the time it takes for the amount of hydrogen produced to reach 20cm3 decreases.

  2. Peer reviewed

    Rates of Reaction

    5 star(s)

    So at any one time less calcium carbonate will be collided with decreasing the rate of reaction. On the other hand if the large solid is broken down the surface area would increase leaving more area exposed. So now there are more area exposed and so there will be more

  1. Chemistry Cwk Rates of reaction: Investigating One Factor Which Affects How Fast Calcium Carbonate ...

    Since the reactions involving the highest three molarities are so close in terms of their rates of reaction its not surprising there is slight deviation. However, the rates of reaction for each individual reaction are significantly lower than their corresponding middle point rates.

  2. The effects of caffeine on reaction time

    Overall while looking at the tables it is seen that ther is a difference in the reaction times. It is almost halved which does show some effect of caffeine on the reaction time. To further test the reliability and accuracy I carried out a statistical test: Z test for matched samples.

  1. Disappearing cross (aka Rate of reaction).

    Thus the higher the temperature the faster the HCL and Sodium Thiosulphate particles move, the faster the rate of reaction thus a speedier time for the solution to become cloudy. The collision theory states that often when the temperatures of both the liquids are increased be 10oc the reaction time is doubled.

  2. Investigating the rate of reaction between hydrochloric acid and calcium carbonate

    and across on the lowest point (line b) and drawing until they join and make a triangle I then divided the length. The gradient is how many squares the line goes up for every square it goes across.

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