• 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 ...

    But this time, two determinations need to be made for every titration in the first method. If there are no definitions of 'orange' or 'colorless', which is actually the case, inconsistency and thus error will occur. Furthermore, this is my first time using phenolphthalein to do titrations since the start of F.6.

  2. Investigating the Rate of the Reaction between Bromide and Bromate Ions in Acid Solution

    + H+(aq) --> HBr(aq) (Equation 3.8.3) Step 2 (fast): BrO3-(aq) + H+(aq) --> HBrO3 (aq) (Equation 3.8.4) These two products, hydrogen bromide and hydrogen bromate, then react together in the rate determining step: Step 3 (slow): HBr(aq) + HBrO3 (aq)

  1. Acid-Base Titrations.

    materials, are generally known by their trivial names as in the above table. A few indicators, of which thymol blue is an example, are polyprotic acids which can change color more than once as pH is continuously increased. Such indicators can be used at a pH equal to either of their pKa values.

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

    The difference between the number of moles of HCl initially added to the antacid and the number of moles of HCl neutralized by the NaOH during the titration is the number of moles neutralized by the antacid. Several antacids will be tested and the relative strengths of each will be compared.

  1. Investigating how concentration affects rate of reaction

    Repeat each concentration 5 times. All other factors such as temperature should be kept constant and the same apparatus should be used each time. Sulphuric acid concentration should be kept at 0.1mol/dm-3 when not being investigated, so that it is not so weak that the reaction takes place too slowly to be measured.

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

    If open sided packing is used the much lower chance. If fouling does occur, there are major operational problems, costs dramatically rise and efficiency falls greatly. Plate columns: more susceptible to fouling due to the larger open areas and smaller holes on the trays.

  1. The Determination of rate equation

    as in the figure below, the gradient of the graph which represents the rate, is the same everywhere whatever the concentration of R. The order with respect to R is therefore zero. First order = If the graph obtained is a curve with a constant half life the, as shown

  2. We are aiming to accurately prepare a standard solution of 0.1 M (mol dm-3) ...

    Aim To calculate the unknown concentration of hydrochloric acid by carrying out a titration Equation The equation for this reaction is: Acid + base ï° salt + water + carbon dioxide Hydrochloric + sodium ï° sodium + water + carbon acid + carbonate chloride dioxide 2HCl + Na2CO3 ï° 2NaCl + H2O + CO2 2 moles of hydrochloric acid (N1)

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