BTEC APPLIED SCIENCE: UNIT 2 - Learning Aim A

Unit 2: Practical Scientific Procedures and Techniques. Learning aim A: Undertake
titration and colorimetry to determine the concentration of solution


Index
 Introduction,
 Risk Assessment,
 Equipment Needed,
 Calibration,
 Method (For Both),
 Results (For Both),
 Graphs (For Both),
 Calculations.
 Conclusion (For Both)
 Evaluation (For Both)

Introduction

This report will show how to determine the concentration of a solution using Titration and Colorimetry.
Demonstrated below is the correct preparation and standardising of solutions for titration and
colorimetry, an investigation into the concentration of unknown solutions using procedures and
techniques in titration and colorimetry, a demonstration of skilful application of procedures and
techniques and evaluated accuracy of procedures and techniques used in titration and colorimetry in
relation to the outcomes and to suggest improvements.



Titration of Sodium Carbonate solution and unknown concentration of Hydrochloric
Acid.


Risk Assessment

 Hydrochloric acid - Corrosive,
 Sodium Hydroxide - Corrosive,
 Indicator - Flammable,
 Sodium Carbonate – Irritant,
 Glassware – Breakages.

In the experiment you will use Corrosive and harmful chemicals, Flammable substances and
Glassware. To reduce the risk of harming yourself and others, in the event of any spillages or
breakages you should clean them up immediately and put any pieces of broken glass in the bin. You
should also limit skin to skin contact with the hazardous substances and use gloves where and if
needed, Have no open flames when using the indicator, be very careful when using the glassware
and chemicals and lastly have a window open at all times to create ventilation to prevent yourself or
anyone else from breathing in strong amounts of the irritant.



Equipment needed:

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,  1M Hydrochloric acid – Corrosive,
 Sodium carbonate – Irritant,
 Phenoplhalein (indicator) – Flammable,
 Sodium hydroxide – Corrosive,
 Balance,
 Spatula,
 Deionised Water,
 Volumetric flask,
 Burette,
 Funnel,
 Pipette filler,
 Pipette,
 Conical flask,
 Beaker,
 pH meter,
 Clamp,
 Stand.

Calibration (For both)

Calibration is important as it ensures that the equipment you are using is more accurate and the result
that you receive will give a more precise outcome. The equipment that you need to calibrate for both
experiments is the Balance, pH meter, Pipette and the Colorimeter. To calibrate the balance you can
use set weights to see if the reading matches the actual weight of the objects, or weigh the substance
you are using multiple times to ensure you receive the same reading. To calibrate the pH meter you
leave it in shallow water for roughly 60 seconds to make sure that the reading is a pH of 7. Thirdly to
calibrate the Pipette you run deionised water through it to make sure that it is clean and practice filling
and emptying the pipette filler. Lastly to calibrate the colorimeter insert a cuvette filled with deionised
water into the cuvette holder, and test it.

Method (Titration)

Step 1. Calibrate all the equipment necessary as shown above,

Step 2. Weigh out 0.25-0.30g of sodium carbonate into a dish,

Step 3. Fill a beaker with 100ml of deionised water, then dissolve the sodium carbonate in the water.
When it has all dissolved put the solution into a 250cm volumetric flask using the funnel,

Step 4. Once the sodium carbonate solution is in the volumetric flask fill it with deionised water up to
the mark and gently swirl it to make sure that all of the substance is dissolved,




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