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

The titrimetric determination of the concentration of sodium hydroxide

Extracts from this document...

Introduction

The titrimetric determination of the concentration of sodium hydroxide 29.1.2010 Abstract Sodium hydroxide is a base often used in titrimetric analysis of drugs. Its concentration is required to be volumetric standard (VS). This means that the exact concentration must be determined by titration before it is used. The "volumetric standard" is defined by the British Pharmacopoeia (BP). "Ascertain the exact concentration immediately before use in the following manner. Titrate 20ml of the solution with 0.1M hydrochloric acid VS using the indicator prescribed in the assay in which the solution is to be used"1 In the BP, standardised solutions are written in italics e.g. 0.1M sodium hydroxide VS . Key Words Burette: a long vessel with a tap at the bottom which is used to measure accurately the volume of a solution added. The scale can be read to an accuracy of half a division e.g. ...read more.

Middle

Materials * Burette & Stand * Bulb pipette (10ml) and filler * Conical Flask (100ml) * Beaker (100ml) * White Tile * Funnel * Hydrochloric acid (0.5 mol dm-3 ) * Sodium Hydroxide (approx 0.4mol dm-3 ) * Distilled water * Methyl orange indicator Method Illustration showing how to set up equipment for titration, reading the meniscus and a sample results table. * The equipment was set up as illustrated * 20ml of sodium hydroxide was pipetted into the 100ml conical flask and approximately 3 drops of methyl orange indicator were added * The flask was placed over the mouth of the burette and the burette was filled with 0.5 M HCl and the volume mark was noted to 2 d.p. (measurement was taken at the bottom of the meniscus) * HCl was added to the conical flask containing the sodium hydroxide 0.5ml at a time whilst swirling to mix the reagents. ...read more.

Conclusion

Concentration = moles / volume 0.01689 dm3 x 0.5 mol dm-3 =8.445 x 10-3 mol 8.445 x 10-3 mol /0.02 dm3 = 0.422 mol dm-3 Discussion The accuracy of the experiment was perceived to be quite good. The results were very close together, the percentage difference was only 1.066%. The values obtained in this experiment were very close to values obtained in the class. Although the 3 values obtained were very similar, if one was very different, it could be omitted as it would skew the average. The burette was read fairly accurately however it was difficult to read on occasion because the scale was only marked up with tenths and not hundreds of a millilitre. Conclusion The purpose of this experiment was to determine the exact concentration of sodium hydroxide through a titration experiment. The concentration of NaOH was determined to be 0.422 mol dm-3. 1 British Pharmacopoeia. Vol IV.2008. Appendix I B. A134. MHRA.London ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Physical Chemistry 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 Physical Chemistry essays

  1. Determination of the Amounts of Sodium Hydroxide Solution and Sodium Carbonate in a Mixed ...

    I forgot the fact that after the end point is reached, which is colorless, further adding HCl into the conical flask will not change the color of the solution. The solution will remain colorless. Errors will occur in this case.

  2. Acid-Base Titrations.

    Let us calculate the pH values along the course of a particular titration, the titration of exactly 100 mL of 0.100 molar acetic acid with 0.100 molar sodium hydroxide. In practice, we would probably titrate 25.00 mL instead for convenience, but these volumes are selected to simplify some of the calculations.

  1. Drug: Antacid Effectiveness Analysis To determine the neutralizing ability of antacids in different ...

    of moles of NaOH required to neutralize excess HCl: No. of moles of NaOH = Molarity � volume = 0.1 � (20.9 / 1000 ) = 0.00209 mol HCl(aq +NaOH(aq --> NaCl(aq) + H2O (l) No. of moles of HCl neutralized by NaOH : 0.00209 mol No.

  2. Investigating how concentration affects rate of reaction

    x 79.9 = 79.9 O3 = 3 x 16.0 = 48.0 RFM = 167 grams needed = (0.01 x 167 x 250) 1000 = 0.4175g dissolved in enough distilled water to make 250ml of solution. 1M Sulphuric acid: H2SO4: H2 = 2 x 1.0 = 2 S = 1 x

  1. The Determination of rate equation

    be few of them to collide so the rate of reaction will differ due to its concentration. A higher concentration of reactants leads to more effective collisions per unit time, which leads to an increasing reaction rate (except for zero order reactions).

  2. Describe the construction, operation and application of distillation equipment used in industry

    Too much of an increase could possibly lead to over-pressuring, a column shutdown or an explosion. c variations in composition As the composition of the incoming feed varies, the pressure and temperature of the column may need to change. If this is not done correctly, then there may be problems in other areas where the column outputs are going.

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