Free Alkali Essays and Papers

Bases and Alkalis A base is a compound that reacts with and neutralises an acid. The reaction forms a salt plus water. Alkalis are a type of base - ones that dissolve in water. Alkalis are compounds that react and neutralise acids. Like bases, they form a salt and water in the reaction. Alkalis turn red litmus indicator paper blue and they cause Universal Indicator paper to turn blue or purple. Alkaline solutions have a pH value greater than 7. Alkaline solutions feel soapy and are

Neutralisation of an Alkali In this investigation, I plan to find a pattern or rule in the neutralisation of an alkali. I plan to use hydrochloric acid and sodium hydroxide. I will use the indicator, phenolphthalein, to tell when the sodium hydroxide has been neutralised, which will turn from purple to clear. The Background of the Reaction ============================== The reaction is neutralisation.Neutralisation is where an acid and alkali are mixed to neutralise the substance

of a more general problem known as Alkali Aggregate Reaction [AAR]. ASR is a chemical process in which alkalis, usually predominantly from the cement, combine with certain types of silica in the aggregate when moisture is present. This reaction produces an alkali-silica gel that can absorb water and expand to cause cracking and disruption of the concrete. For damaging reaction to take place the following need to be present in sufficient quantities. High alkali cement Reactive aggregate [e.g. crushed

Investigating Temperature Change when Different Volumes of Acid and Alkali are Mixed Prediction ========== My prediction is that the biggest temperature change will be when there are equal amounts of H+ ions and OH-, this is because create an optimum mixture for the ions to neutralise each other. Apparatus ========= v Empty plastic yoghurt cup v thermometer v Hydrochloric Acid v Sodium Hydroxide v Two measuring cylinders [IMAGE] Diagram =======

Limewater (alkali) - Irritant. * Phenolphthalein - May cause irritation of the respiratory and digestive tract if ingested. The reaction between the hydrochloric acid and limewater will also produce calcium chloride and water both of which have no hazards and are not dangerous at all. Phenolphthalein will not react with any of the other chemicals to produce anything dangerous. Also any reaction involving HCl can often be quite violent so great care must be taken however acids and alkalis tend

changing the concentration of an alkali, on the volume of acid needed to neutralise it, when acid is added to it? The plan is to use two acids (Hydrochloric & Sulphuric) and one alkali (Sodium Hydroxide). The reason I need to use two acids is; because the question applies to all acids and alkalis and to just use one of each would not enable me to come to a general conclusion. If there had been more time available, ideally I would have preferred to use two alkalis as well as two acids. Predictions

Analysis and Evaluation of Neutralisation An example of neutralisation is this: [IMAGE]Acid or Alkali + Base Salt + Water + Hydrogen This investigation will investigate the reaction of hydrochloric acid and sodium hydroxide where these two liquid compounds neutralise each other. We will be monitoring the temperature of the liquids as more of the hydrochloric acid (HCL) is added. [IMAGE]Sodium Hydroxide + Hydrochloric acid Sodium Chloride + water [IMAGE]NaOH + HCL NaCl + H2O I

Substances that neutralize acids are called alkalis. An acid is a substance that forms hydrogen ions (H+ ) when placed in water. It can also be described as a proton donor as it provides H+ ions. An example of an acid is hydrochloric acid (HCl), Sulphuric acid (H2SO4) etc. An alkali is a soluble base and forms hydroxyl ions (OH-) when placed in water. It can be called a proton acceptor and will accept hydrogen ions to form H2O. An example of an alkali is Sodium Hydroxide (NaOH). Neutralization

Method/Plan of the experiment: First of all, I will set up the apparatus as the diagram shows: Then, I will measure out the acid and alkali using the measuring cylinder. Once I have done that, I will pour the 25ml of Hydrochloric Acid in to the conical flask. I will also pour the 25ml of Sodium Hydroxide into the burette, and adding 1cm cubed of alkali at a time into the conical flask, I will record the temperature of the solution made by the two substances. By now, I will have also put

Acidic solution contains excess of hydrogen irons fl*(ad). An alkali is a solution that has a ph more than 7 also contains a base soluble in the water. For example Magnesium oxide when an acid necats with an Alkali salt and water is formed. The reaction between an Acid and alkali is exothermal which means the heat escaping this solution with a ph7 is neutral. Neutralisation is a reaction in which an Acid reacts with a base or Alkali. Neutralize ions can be replaced as the reaction acid +base=salt