Preparing Standard Solution of Sodium Hydroxide Essay
Method 1. 4g of sodium hydroxide was weighed using the 0. 1g balance and put into a small beaker. The small beaker and its contents were weighed using the 0. 01g balance and the mass was recorded. The contents of the small beaker was transferred into a large beaker and the small beaker weighed again using the 0. 01g balance. The mass was recorded then de-ionised water was added down the side of the large beaker. 150cm3 of water was used and swirled to mix the contents of the beaker.
A glass rod was used to dissolve the solid completely. The solution was then transferred into a volumetric flask using a funnel. The beaker, rod and funnel were washed using the de-ionised water with the washings going into the flask. The mark on the volumetric flask was made up with the de-ionised water and shaked to mix the contents. Last of all the flask was labelled. Titration of hydrochloric acid. Definition of Titration A procedure which is used to determine the concentration of an acid or base.
A measured volume of an acid or base of known concentration is reacted with a sample to the equivalence point. Method First the hydrochloric acid solution was prepared. A volumetric flask was filled with 75% water. Then using a funnel hydrochloric acid was added into the volumetric flask. Then residual of hydrochloric acid was rinsed from the graduated cylinder and the funnel into the volumetric flask using three 5ml portions of distilled water. The flask was gently shaked.
Next the volumetric flask was filled to the 1000ml mark. The flask was shaked again. The volumetric flask was labelled. A burette was rinsed with 5ml of 0. 1 M hydrochloric acid solution. The rinse solution was discarded. The rinse was repeated two more times. The burette was then filled with 0. 1 M HCL solution. The volume was adjusted to the zero mark. A second burette was filled with the prepared 0. 1 M sodium hydroxide solution. 15ml of 0. 1 M HCL was added into a clean 250ml beaker.
Then 50ml of distilled water and 2 drops of phenolphthalein indicator solution were added. The volume of 0. 1 M HCL used was recorded. The HCL solution was titrated with 0. 1 M NaOH. When the end point was reached the solution turned pink. The titration was allowed to continue for 10 more seconds after a permanent pink colour was obtained. The volume of 0. 1 M NaOH used to reach the equivalent point was determined. The 250ml beaker was rinsed with distilled and deionised water. The titration procedure was repeated 2 more times.