Determine Unknown Element in Monoprotic Acid

Essay by jinting April 2010

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To determine unknown element of acid, just titrate it against a solution of bases of known concentration. Chemical characteristic of dragon fruit and red cabbage would be explored in the experiment and colour range of dragon fruit juice and red cabbage juice at different pH would be determined. The objective of the experiments also was to know the characteristic of acidic gas and alkaline gas.

Acids are compounds which donate H+. Meanwhile, bases are simply defined as compounds that produce OH- ions. Neutralization of acids occur when they react with bases to form salt and water molecule at pH 7. Strong acids and bases dissociate completely in water but weak acids and bases dissociate slightly. When the color of an indicator is used to test for neutralization, the final pH may differ from pH 7 depending on the indicator used. It will also differ from pH 7 in reaction between strong acids and weak bases, weak acid and strong bases.

This is because the salt formed will have acidic or basic properties respectively.

Titration was used to study acid-base neutralization reaction quantitatively. It is a volumetric technique used to determine the concentrations of solutions. A titration involves the addition of a titrant to solution of unknown concentration until it reaches an equivalence point. The equivalence point was the point at which the acid was completely reacted with or neutralized by the base. The point was signaled by a changing of color of an acid-base indicator that had been added to the acid solution.

An acid-base indicator is often a complex organic dye that undergoes the color change when the pHchanges over specific values. They can be used in the titration of a wide range of weak acids and bases. Many plant pigments and other natural products are good...