• 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)

    'If the acid is of a higher concentration, the reaction will be quicker.'. Also if the particles have more energy, they will be travelling faster, making them collide more frequently. PREDICTION When the concentration of acid increases, more gas will be given off faster.

  2. Factors Affecting the Rate of Catalytic Decomposition of Hydrogen Peroxide.

    if the relationship would continue afterwards would be to actually do the experiment with an expanded range), and there are some anomalous points - these however will be accounted for in the evaluation. Evaluation My results clearly support my prediction, and seem reasonably reliable as most points lie near the

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

    The temperature must still be kept constant so that the rate of reaction is not affected during the experiment. To achieve this the experiment will be conducted in a water bath at a temperature of 30 �C, above room temperature, but below the optimal temperature.

  2. The Iodine Clock Investigation

    The following graphs show results typical to first order reactions: The first zero order graph showing concentration vs. time is such that the time it takes for the concentration of the reactant to be halved is constant; this is known as half-life.

  1. Investigate how concentration of hydrochloric acid (HCL) affects its reaction with calcium carbonate (CaCO3).

    At 1 molar the gradient was 0.18cm3/s, at 2 molar the gradient was 1. From this I can again see that the effect of doubling the concentration more than doubles the rate of reaction. The results did not fully support my prediction, reasons for this could have been: * The gas syringe was sometimes jerky.

  2. How does varying the concentration Rennin affect the coagulation time of Milk

    I predict the graph to show an increase in rate of reaction corresponding to an increase in the concentration of rennin. Eventually though the graph will straighten out with a constant and maximum rate of reaction for the controlled amount of milk.

  1. The Effects of Temperature on the Function of Catecholase

    with another lab group, group A-4, to cover all of the temperatures required. Methods To properly perform our experiment, we needed to have catechol (the substrate), catecholase (the enzyme), and water to allow the reaction to occur in. We also needed some means of manipulating the temperature, and some way to determine the rate of the reaction.

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

    We took the temperature of the solution left in the buckler flask after the experiment. We removed the bung when the experiment had been going for 1 minute. We noted down how much carbon dioxide was produced and washed out our buckler flask with distilled water after the experiment to get rid of contaminates.

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