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identify 4 buffer solutions and their uses

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Introduction

Amanda Evans 1.5 identify examples of buffer solutions and their practical uses Changes in pH can harm cells and any living organisms. Buffers are solutions that resist changes in pH when acids or bases are added to them, consisting of weak acids and their conjugate bases. The concentrations of the weak acid and the salt are large in contrast to the amount of protons/hydrogen's that are added or removed. Water or simple aqueous solutions do not maintain their pH well because of the effects of impurities such as carbon dioxide. Solutions can be made with a constant pH even if small quantities of acid and alkali are added to it. 1) Natural buffers are chemicals that the body releases into the blood stream to help maintain a healthy pH level. Carbon dioxide (CO2) acts as an acid by donating hydrogen ions when needed and forms carbonic acid when it dissolves in water. Carbonic acid bicarbonate is important for maintaining an acid base balance in the blood as it equalizes the pH (7.5) ...read more.

Middle

The zwitterionic buffer can stabalise the activity of enzymes by preventing large pH shifts during freezing. Water will freeze and ice crystals will grow in a typical buffer composition and as the temperature approaches the eutectic points of the salts that are present, the less soluble salts crystallise out of the solution first. This can cause massive changes in pH before the frozen solid is formed. The zwitterionic buffer may prevent the shift in pH, maintain the acitvity and stabilise the enzyme. 3) Saliva in the mouth has a buffering capacity, as the pH of the mouth must be kept near neutral for things such as tooth maintenance. The oral pH is buffered to a small extent by saliva proteins and phosphate. Buffers neutralises acids in the mouth based on systems such as the phosphate system and the carbonic acid/ bicarbonate system. A very important buffer is bicarbonate in solution neutralising the acids in the mouth. ...read more.

Conclusion

All Mineral weathering 10 - 3 Soil organic matter 4 - up Exchange reactions 4.2- 2.8 Aluminum oxides and hydroxides 3.8 - 2.4 Iron hydroxides and oxides < 3 H+ from water 5) Acid rain is a form of precipitation formed from air pollutants such as sulphur dioxide and nitrogen oxides, which are released as gasses into the atmosphere. The gasses are from the burning of fossil fuels such as coal etc. the gasses combine with moisture in the air to form sulphuric and nitric acid solutions that fall to the earth. The effect of acid precipitation can have devastating effects on aquatic animals and vegetation. A healthy lake has a pH value of 8, which is slightly basic which is maintained by the presence of buffering solutions in the water. The buffering chemicals in a lake provide an indication to the types of rocks, soils and minerals in the surrounding area. Providing buffering materials can be obtained from the rocks, soils and minerals the alkalinity levels may be restored to normal. ...read more.

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