Chemistry Assignment

Experiment 1 : Titration

Objective :

To determine the concentration of  a solution of sulphuric acid using                    standard sodium hydroxide solution.

Procedure :

1. 25.0cm3 of sulphuric acid was pipette into a conical flask.
2. 2-3 drops of phenolphthalein were added and the solution with the standard NaOH was titrated until the first permanent pink colour is observed.
3. The procedure were repeated for consistent results.

Results :

Discussion :

Acid-base titration was used to determine the concentration of a solution. The process of titrating utilizes a solution of unknown concentration, which is either an acid or a base. A solution of known concentration was then added to the solution being testing. The added solution was the opposite of what the tested solution is: If one was a base, the other was an acid. "neutralization reaction" happen when this two solution reacted.  The amount of one required to exactly neutralize the other tells you when the amount of acid and base are equal. The known concentration can therefore be used to calculate the unknown concentration.   Type of titration most common were acid-base titrations. During the experiment we have make some mistake that cause us cannot get the accurate reading. First we have carry out parallax errors while the experiment going on. Next we dint wash instrument properly before started the experiment. We also dint shake the solution while adding the NaOH. Therefore, we cannot get the accurate reading and permanent pink appear. The way to prevent parallax error were put eye on perpendicular while reading the measure to get the accurate reading. Besides that, wash the instrument properly before started the experiment to prevent the chemical left over to affect the result. We have to shake the solution while adding NaOH because it will help the solution to mixed up equally. As result, we can get a permanent pink in the end of result