• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9

Chemistry: Practical Investigation

Extracts from this document...

Introduction

Chemistry: Practical Investigation Aim To see how varying the concentration of hydrochloric acid affects its reaction time with calcium carbonate. CaCo3 + 2HCl CaCl2 + H2O + CO2 Apparatus In this experiment I will need: Hydrochloric acid, calcium carbonate, water, conical flask, a bung with hole for tube, burette, water basin, eye protection, stopwatch. Background science "A reaction rate is the speed at which reactants are converted into products in a chemical reaction. The reaction rate is given as the instantaneous rate of change for any reactant or product"1. Collision theory is the theory that atoms or molecules need to collide to react. Most, if not all, reactions also need activation energy for the reaction to occur, also orientation is needed. Factors affecting collision theory are surface area, catalysts, temperature and concentration. Surface area affects the rate of reaction because it increases the frequency of collisions as there is more to collide with, temperature affects the rate of reaction because it both increases the frequency of collisions and the energy in the collisions as it excites the atoms, while concentration affects the rate of reaction because it also increases the frequency of collisions as there are more atoms to collide into the calcium carbonate. ...read more.

Middle

Once done repeat the experiment using different concentrations of HCL (diluted with water) with ratios of acid: water as shown:- 1:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, 1:9. I decided on using a burette instead of a boiling tube or measuring cylinder because a burette is more precise and accurate, this is also the reason why I used a stopwatch instead of counting. Despite this they are not 100% accurate so some error margin in produced. Factors involved in this experiment include temperature, concentration and surface area. The factor I have decided to change is concentration. I will be able to change this factor by diluting the hydrochloric acid with water and I will keep the other factors the same by monitoring the temperature to keep it at a steady rate and by weighing the large chips of calcium carbonate each time so the experiment is fair. I use large chips because it is a slower reaction and so will leave less room for human error. I will use 10 different concentrations to increase the range of results and I will repeat the experiment three times for concentration to ensure any outliers can be found and discarded so to make sure that the data I will collect will be accurate and reliable, leading to a good quality of evidence on which to base my decision. ...read more.

Conclusion

Trends seen from the graphs show a positive correlation however it is not proportional meaning that the rate is affected greater at higher concentrations compared to lower concentrations and thus reaction gets faster towards the end, making the gradient progressively more. Conclusion From this experiment I can conclude that the concentration of an acid does have an effect on the rate of reaction because of collision theory. Evaluation Due to human and apparatus error then the concentration has ~0.05cm3 error, while the rate has an error of ~ 1 second and 0.5cm3 The results aren't proportional due to many factors. This experiment is exothermic and so the temperature increase may affect the results, also there is no way to get precisely the same surface area of calcium carbonate as they weren't pre-cut to specification. The level of confidence in the results is low because of the many outliers in the lines of best fit because of this the data is insufficient and unreliable. Ways in which I could improve the experiment and results would be to carve out calcium carbonate chips to a specific surface area, while using a cooler to effectively reduce the temperature increase caused by the thermal energy being transferred. ...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

Here's what a teacher thought of this essay

3 star(s)

This report is fairly well written, supported by some strong scientific theory. Specific strengths and improvements have been suggested throughout.

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 Patterns of Behaviour essays

  1. Marked by a teacher

    Marble Chips and Hydrochloric Acid.

    4 star(s)

    The rate of a chemical reaction is a measure of how fast the reaction takes place. It is important to remember that a rapid reaction is completed in a short period of time.

  2. A-Level Investigation - Rates of Reaction – The Iodine Clock

    Using a 200ml measuring cylinder - fill to the approximate level from the water tank then use a dropper to correct to the exact amount. Add this to the second flask also. (6). The first experiment is now prepared. Holding the flask over a white tile, transfer the contents of

  1. The effect of aspirin on the action of bovine liver catalase

    Hypothesis Aspirin will inhibit the action of bovine liver catalase. This means that increasing the concentration of aspirin will decrease the rate of the catalase-aided reaction which breaks down hydrogen peroxide into water and oxygen. Control of variables pH- All enzymes have an optimal pH, any solution that is either

  2. To Compare the Concentration of the Enzyme Catalase in Plant v. Animal v. Fungal ...

    In the first different pH buffers were used to find out the effect of pH on the enzyme. In the second different concentration of inhibitors were used to test the effect of inhibitors on enzyme. In both experiment the 5g of tissue was placed in the test tube along with in the first experiment different pH buffers (5cm3)

  1. The effects of caffeine on reaction time

    Variables: My independent variable is the reaction time taken for the students to do the maths problems. This is a continuous variable. My dependent variables are qualitative variables: age group and emotional state. I took the age group 15-18. I took 5 people of each group so 20 individuals in all.

  2. Determining the Enthalpy Change of the Decomposition of Calcium Carbonate.

    Evaluation The enthalpy change for the reaction CaCO3 (s) heat CaO (s) + CO2 (g) Should have been +178 Kj mol -1 , this figure was according to the text book 'understanding chemistry for advanced level ' Errors must have occurred in the experiment because my result for the (H3 was over 100 Kj mol -1 out.

  1. How Does the Changing Temperature Affect the Rate of Fermentation by Yeast.

    I will ensure that I get precise measurements by using suitable equipment, like a balance for measuring the mass of yeast, and a small syringe for measuring the amount of glucose solution. I will read off the volume of gas from the measuring cylinder carefully to ensure accuracy.

  2. How does the concentration of HCl affect the rate of reaction with CaCO3?

    27.20 27.10 26.90 33.20 N/A 27.07 60.00 0.45 24.00 25.00 0.75 32.10 31.90 31.90 N/A N/A 31.97 60.00 0.53 24.00 25.00 1.00 35.30 34.20 34.50 N /A N/A 34.67 60.00 0.58 24.00 25.00 1.25 41.20 40.90 41.00 40.60 35.60 41.03 60.00 0.68 24.00 25.00 1.50 45.10 45.20 44.90 40.30 N/A

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