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

Agar Diffusion Investigation

Extracts from this document...


Biology Coursework Plan Introduction Having considered the phenomena of diffusion and osmosis I have been told to do a piece of coursework to investigate the rate of diffusion when using different concentrations of acid. I have been told to use Agar. Agar is extracted from sea weed and after dissolving in hot water it cools to form a 'solid' jelly although 99% of this is water. The agar is an inert medium that I am going to use to investigate the rate of diffusion. The agar I will be given has been made alkaline by adding a small amount of NaOH and has the indicator (phenolphthalein) incorporated which is pink in alkaline conditions. As the H+ ions from the acid diffuse in the indicator within the agar will become colourless. ...read more.


* Ensure a good supply of paper towels is available in the event of a spillage and be sure to wipe up any spillages immediately before they escalate. Preliminary Variables I am going to investigate what variables I am going to change during my preliminary investigation. During my preliminary investigation I am going to investigate how both concentration and volume of HCl effect the time taken to turn the phenolphthalein colourless. I am also going to investigate what amount of Agar jelly solution should be used. I am going to use a cork borer and a straw to cut pieces of the agar jelly solution and compare results between the two. Preliminary Investigation Method To being with obtain one test tube rack and one stopwatch. ...read more.


Now return the six test tubes to the test tube rack and repeat the experiment only this time varying volume of HCl used instead. Once all six test tubes have their appropriate agar jelly solution added, add 15ml, 10ml and 5ml of 0.5M HCl to the test tubes one by one and start the stop watch, adding the different volumes of HCl to one of the different sized agar solutions each: As before wait until the agar has turned completely colourless in the first test tube then record the time taken and repeat the process for the next test tube. Preliminary Investigation Results Concentration Cork Borer Sized Agar (Time Taken - Seconds) Straw Sized Agar (Time Taken - Seconds) 1M 0.5M 0.2M Volume 15ml 10ml 5ml ?? ?? ?? ?? Dean Lancaster Page 1 26/04/2007 ...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 Aqueous Chemistry 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 is an reasonable piece of work. The student has a clear idea of what needs to be done, however a little more attention needs to be paid to making the plan as effective as possible.

3 stars

Marked by teacher Kate Gardiner 17/10/2013

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 Aqueous Chemistry essays

  1. Indigestion Tablets Investigation

    Type and concentration of acid I will be using hydrochloric acid for all my experiments, as this is the same acid as that found in the stomach and therefore the reaction will be similar to that which could occur inside the body when somebody takes an indigestion tablet.

  2. Investigating the effects of varying pH levels on the germination of cress seeds

    * After 24 hours, I will weigh each sample and record the results. I will also take note of any physical changes that have occurred. * I will add a further 10cm� of each solution to the corresponding sample Petri dish.

  1. In this experiment, we aim to investigate the effect of sodium carbonate on hard ...

    Firstly, there was a problem with temperature. Unfortunately, the temperature of the laboratory when we conducted the experiment was beyond our control, and it could have fluctuated and had an effect on the results in the process. Secondly, the temperature of the water used for the tests may not have been entirely constant, either.

  2. Determination of the equilibrium constant for esterification of ethanoic acid and propan-1-ol by using ...

    instead of grease which can a much better performance in sealing the joints. This can prevent the volatile substance to escape away from the system through the leakage.

  1. Determination of the vitamin C content (ascorbic acid) of a commercial vitamin Ctablet and ...

    + 5 I- (aq) + 6 H+ (aq) = 3I2 (aq) + 3H2O (l) to occur instantaneously. I2 (aq) is then rapidly produced which lacks stability due to the volatility of the solute. Iodine can loss from an open vessel in a relatively short time.

  2. Antacid Experiment.

    you shall times this by 1000 to get it in cm cubed so it shall equal = 0.2 cm cubed to neutralise the antacid. Predicted volume= 0.2 cm cubed + 13.6 cm cubed = 13.8 cm cubed of acid needed to neutralise the tablet Calculations for Boots antacid tablet.

  1. Gcse Coursework Acid Rain Investigation

    Most atmospheric pollutants are linked to industrial processes, for example smoke from factories, SO2 and NOx from power stations, pollen from agricultural activities, dust from building construction and asbestos from insulating material. Of these the emissions from factories and power stations have been linked to acid rain.

  2. Penguins Investigation

    * Measure 10 ml in the cylinder * Pour 10ml of water in all of the tubes. * Start the clock * Take the temperature of one tube of each layer each minute for 15 minutes. * Record results. EXPERIMENT 2 * Heat the water (750C)

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