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

Analysing; The Reaction of Hydrogen Peroxide and Iodide ions

Extracts from this document...

Introduction

Skill 3: Analysing; The Reaction of Hydrogen Peroxide and Iodide ions

Table of Results

Experiment

Volume of KI used (dm3)

Volume of water used (dm3)

Concentration of I- ions

Time taken for colour to appear (S)

A

5.0 x 10-3

0.020

0.02

9:56

B

0.010

0.015

0.04

5:36

C

0.015

0.010

0.06

4:07

D

0.020

5.0 x 10-3

0.08

3:27

E

0.025

0.000

0.1

2:40

We calculate the concentration of I- ions by following these stages (taking the hypothetical value of experiment A)

Number of moles of KI contained         = volume x concentration

                                        = 5.0 x 10-3 x 0.1

= 5.0 x 10-4 moles

                                        = Number of I- ions contained in the solution

Concentration of solution                = number of mols

                                        Volume of solvent

                                        = 5.0 x 10-4 / (25/1000)

                                        = 0.02 mol/dm3

Thus I have calculated the other values, which appear on the table

Analysis

Derived from the rate equation

Log (1/time) = n log (volume of KI) + constant

We can calculate the rate

...read more.

Middle

-2.53

C

-1.82

247

-2.39

D

-1.70

207

-2.31

E

-1.60

160

-2.20

Thus, we could derive the gradient of the graph, by drawing it, as seen upon the nest page.  


We could also use the statistical method of finding the equation of the regression line, which is:

Y = a +bx (where y and x are the axis's)

B =         (xI - x)(yI -y)

(xI - x)2

a = y - Bx

Where  y = average of all y values

x = average of all x values

xI = x value

yI = y value

Therefore, when an equation is formed, we can mathematically derive the gradient, as the gradient of the graph, mathematically is the constant in front of x, providing y has no constants.  

Thus B =         (xI - x)(yI -y)

(xI - x)2

        = 0.796

        = 0.80

therefore, the order of reaction, with respect to the iodide ions is 0.80.

Maximum error of reading an apparatus        = maximum error x 100

                                                       Amount read

Maximum error of 5 cm3 pipette        = 0.1/ 5 x 100

                                        = 2%

Maximum error of 10 cm3 pipette        = 0.1/ 10 x 100

                                        = 1%

Maximum error of burette         = 0.15/25 x 100

                                = 6.0 x 10-3 %

Maximum error of measuring cylinder        = 0.5/25 x 100

                                                = 2%

...read more.

Conclusion

There could have also been substances that were left in the beaker or pipette, thus the actual experiment that was performed did not include these leftovers.  A way of avoiding this is to ensure that they would be "washed" and when transferring solution from a pipette, to ensure all the solution has come out, it would also be suggested to touch the surface of the solution with the pipette.

One way in which should not have affected the reaction, but probably did, is our concentration span, while waiting for the solution to turn colour, we became increasingly distracted by the surroundings, and hence, at times may have missed the actual time of which the solution changed colour, thus could have affected the results, even though in a very minor way.

        Other ways of improving this experiment would include the use of a pipette instead of a measuring cylinder; even a burette would increase accuracy of the reaction, as a measuring cylinder is quite inaccurate.  Another way of improving the reaction is by using a higher concentration of the solutions.

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Core & Pure Mathematics 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

See related essaysSee related essays

Related AS and A Level Core & Pure Mathematics essays

  1. Marked by a teacher

    The Gradient Function

    5 star(s)

    1 2 1.001 2.006006002 6.012006 x x3 2x3 gradient 1 1 2 6 2 8 16 24 3 27 54 54 4 64 128 96 After looking through each value, I have observed a pattern. I have noticed that the gradient is always equal to 6x�.

  2. Marked by a teacher

    Estimate a consumption function for the UK economy explaining the economic theory and statistical ...

    3 star(s)

    This can be shown in the figure 2(b) as well. Figure 1(a) and Figure 2(b) looks similar. Figure 2(b) displays a pattern. That is we are not confident with our model. After closer examination of the tests, however, indicates that both these two Absolute income equation did not predict the actual consumption well from 1948 to 2002.

  1. Exponential decay:The objective of this experiment is to get the trend line of heart ...

    Because some people ran fast, some people ran slowly. 3.0 Analysis 3.1 Experimental value From the graph, we can get the equation, 155.89 can be rounded to 156 which is the original number of heartbeat after excising. -0.0934 is the decay constant which represent . 3.2 Data Analysis This is the heart rate that our body will decrease to after an exercise session.

  2. The Gradient Fraction

    method: Tan ? method The Tan ? method is very similar to the Triangle method. It is not as accurate as the Increment method, but can be used to give an estimate of the gradients. First of all, you will need to draw a tangent on the curve.

  1. Experimentally calculating the wavelength of an He-Ne laser by means of diffraction gratings

    = x/L, but since the angle would be so minute, one can use the equation: ? = x/L. Since the angle would be so minute, sin? would also be approximately ?. Therefore: ? = (dsin?)/m ? = (dx)/(mL). Hypothesis: If one shines a He-Ne laser through different diffraction gratings and

  2. Examining, analysing and comparing three different ways in which to find the roots to ...

    I will then begin by using 1 decimal place, and I put the values back into the equation in order to get the values of f(x). I calculated each of the f(x) values in order to see where the change in sign was, as shown in the results below: 4

  1. Three ways of reading The Bloody Chamber.

    At the first level, the key being inserted into the lock is a signifier, whose signified is the idea that secrets are being uncovered. The sign at this first level semiological account is the 'secrets uncovered' key. At the second mythic level of semiological analysis, the sign from the first level, the 'secrets uncovered' key now functions as the SIGNIFIER.

  2. Although everyone who gambles at all probably tries to make a quick mental marginal ...

    It is obvious that the payoff and the odds have an inverse relationship: Fig. 1: The function to relate payoff and odds will be found through linear regression. The line appears to be quadratic in nature, thus I hypothesize that the equation will be in the form:.

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