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

To compare the concentrations of some alkalis in saturated solutions.

Extracts from this document...


Chemistry Planning Exercise To compare the concentrations of some alkalis in saturated solutions. Apparatus 25cm3 pipette pipette filler Conical flask Burette Stand Saturated solution calcium hydroxide Saturated solution sodium hydroxide Saturated solution magnesium hydroxide Saturated solution potassium hydroxide Hydrochloric acid, various concentrations (see table) Methyl orange indicator Concentrations of acid used To find the concentration of acid that was most appropriate to use, the solubility of the above hydroxides in water was found and converted into concentration of saturated in moldm-3 (see appendix A)1. A similar concentration of acid is used so that the volume of alkali used in the titration is reasonable. Name of Alkali Concentration of saturated solution / moldm-3 Concentration of hydrochloric acid used / moldm-3 Calcium hydroxide 0.020 0.03 Sodium hydroxide 0.27 0.20 Magnesium hydroxide 0.00015 0.00020 Potassium hydroxide 0.20 0.20 Method - Pipette 25cm3 of 0.02 moldm-3 hydrochloric acid into a conical flask by using a pipette filler to fill the pipette up to the line and then emptying the pipette into a conical flask. ...read more.


The acid and alkalis used are corrosive. If spilt, clean up immediately. If spilt on skin, wash thoroughly with cold water for 10-15 min. The glassware used is very delicate and should be handled with great care. If any glass is broken, it should be reported and swept up immediately. To show how calculations are carried out to find the concentration of saturated solution of the hydroxide Table of suggested volumes of alkali required to neutralize the acid Alkali Suggested volume alkali required to neutralize the HCl / cm3 Volume of hydrochloric acid used / cm3 Concentration of acid used / moldm-3 Calcium hydroxide 18.7 25 0.02 Sodium hydroxide 18.5 25 0.20 Magnesium hydroxide 16.7 25 0.00020 Potassium hydroxide 25.0 25 0.20 To calculate concentration of calcium hydroxide Ca(OH)2 (aq) + HCl (aq) --> CaCl2 (aq) ...read more.


+ H2O (l) 1 mol KOH --> 1 mol HCl 1 mole = (25 x 0.20) / 1000 = 0.005 mol Number of moles KOH = 0.005 mol Thus concentration= (1000 x 0.005) / 25.0 = 0.20 moldm-3 Appendix A The solubility in water (100 x the mass of anhydrous solute per unit mass water) was found using Chemistry data book JG Stark HG Wallace Second edition 1982 p62 The concentration in water in gdm-3 was found by dividing by 100 to give the solubility of the anhydrous salt per 1 g water, and then multiplying by 1000 to give the solubility per dm-3 water. The concentration in moldm-3 was found by dividing the concentration in gdm-3 by the relative atomic mass. Hydroxide Solubility in water (100 x the mass of anhydrous solute per unit mass water) Concentration in water (gdm-3) Relative atomic mass Concentration in water (moldm-3) Calcium hydroxide 0.156 1.56 74.1 0.02 Sodium hydroxide 109 10.9 40 0.27 Magnesium hydroxide 0.0009 0.009 58.3 0.00020 Potassium hydroxide 112 11.2 56.1 0. ...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

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. Acidic Solutions.

    If stabbed, seek medical advice. Glass ware Breaking /stabbing Common sense Use proper procedure If broken, do not touch, use parker and brush to pack into the broken glass container. If stabbed, rinse under running water and plaster. Seek medical advice.

  2. Determine Solubility of KClO3 Salt.

    Therefore you cannot obtain the solution from what you have pipetted. Next step of the experiment is put the crucible on a hot water bath. The purpose of putting the crucible on a hot water bath is let the KClO3 solution to evaporate until dry.

  1. Indigestion - find out the composition of tablets which are for indigestion and compare ...

    In addition Bisodol indigestion relief tablets contain saccharin, maize starch, sucrose, calcium stearate and peppermint oil flavouring. 30 tablets Price: �1.95Including VAT at 17.5% Rennie Peppermint Calcium carbonate Ph Eur 680mg and heavy magnesium carbonate Ph. Eur 80mg. Each tablet also contains: Sucrose, glucose (250mg), peppermint flavour, talc, providone, saccharin sodium, magnesium stearate.

  2. The determination of the solubility of calcium hydroxide.

    * This is the end point of the titration. * Record your reading on the burette as a rough one, then repeat 3 times and record results in a table. How to dilute and why to dilute: The hydrochloric acid has to be diluted in order for it to react effectively with calcium hydroxide.

  1. Determining the Solubility of Calcium Hydroxide.

    total amount I need as I don't know how many titrations I will carry out. Justification of Method During this experiment I have decided to use a burette as it has a large resolution- i.e. it can be read very accurately.

  2. Comparing the Concentration of Some Alkalis in Saturated Solutions.

    Distance of outer electron from nucleus increases; 3. Increases shielding of positive nuclear charge ?outer electrons held less tightly; 4. Increased electron repulsion. The increases size of metal ions at the base of groups one and two means that the distance between OH- and X+/2+ ions will be greater, therefore the electrostatic attraction between them is less.

  1. Compare the concentrations of some alkalis in saturated solutions.

    Any splashes must be rinsed off immediately. Concentrated metal hydroxides are very corrosive so goggles must be worn and any splashes rinsed off immediately. Phenolphthalein is toxic so care must be taken when in use. Don't swallow any phenolphthalein and rinse your hands after use.

  2. Compare the concentrations of some alkalis in saturated solutions.

    In order to suggest a standard concentration of HCl we need to look more carefully at the concentrations of the saturated solutions of alkali. The acid must have a low concentration, so I will look at group II first because their concentrations are lower than group I.

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