An investigation of neutralization reactions Essay -- GCSE Chemistry C

An investigation of neutralization reactionsAimQuestion What is the effect of changing the concentration of an alkali, on thevolume of acid needed to pay off it, when acid is added to it?The end is to use cardinal acids (Hydrochloric & Sulphuric) and angiotensin converting enzyme alkali(Sodium Hydroxide). The reason I need to use two acids is because thequestion applies to all acids and alkalis and to just use oneness of apiecewould not enable me to come to a general conclusion. If there had beenmore time available, ideally I would have preferred to use two alkalisas well as two acids.PredictionsFirst of all, here are the definitions for an acid and an alkaliAn acid is a substance that forms hydrogen (H+) ions when placed inwater. It loafer also be described as a proton donor as it provides H+ions.An alkali is a soluble base and forms hydroxyl ions (OH-) when placedin water. It can be called a proton acceptor because it bequeath accepthydrogen (H+) ions and form H2O.A Hydroc hloric acid molecule (HCl) will release one H+ ion and one Cl-ion when placed in water. A Sodium Hydroxide molecule (NaOH) willrelease one Na+ ion and one OH- ion when placed in water. This meansthat one molecule of NaOH and one molecule of HCl will neutralise eachother and produce H2O and a neutral salt called Sodium Chloride(NaCl). This means that to neutralise HCl and NaOH when they are atthe same concentration, you need equal amounts of each. GRAPHOn the other hand, a Sulphuric Acid molecule (H2SO4) will release twoH+ ions and one SO4-- ions. This means that you need two molecules ofNaOH to neutralise one molecule of H2SO4 and produce the neutral saltSodium Sulphate (Na2SO4). This means ... ... in thefollowing ways * Instead of using Universal Indicator, I would use an indicator which only changed colour when the solution was Neutral rather than gradually changing as the pH became lower (e.g. Methyl Orange or Phenolphthalein).* To get the pH more ac curate next time, a pH meter could be used.* To get it very accurate, the acids and alkalis supplied should be an exact amount (I am not sure whether the ones I used were exact). * To use very recently distilled water, because the water will become acidic if left for a long time.ReferencesBooksDunstan, S. 1968. Principles of Chemistry. Van Nostrand Reinhold Pages 187-88 Pages 215- 253McDuell, B. 1997. GCSE Chemistry Classbook. Letts Pages 171-72 Pages 28-32 Page 262Computer programsMicrosoft Excel Version 97Microsoft Word 97 key Shop Pro 4