Полнотекстовый поиск:
Где искать:
только в названии
только в тексте
слова в тексте
только заголовок

Рекомендуем ознакомиться

Остальные работы->Реферат
A civil war that has raged for seven years in the small West African country of Sierra Leone has turned increasingly brutal. (1, p.1) Rebels are mutil...полностью>>
Остальные работы->Реферат
You never really understand a person until you consider things from his point of view (30). Atticus Finch, a popular lawyer, and the father of the mai...полностью>>
Остальные работы->Реферат
I advocate free speech at every turn. Machines should enhance it, but certainty not replace our right to use our collective voices. If we can advance ...полностью>>
Остальные работы->Реферат
From: babenes@wco.com To: QUICKPAPERS@TOTALLY.NET Subject: Submit a paperDate: Thursday, November 06, 1997 7:06 PMTitle: CensorshipCategory: otherDesc...полностью>>

Главная > Реферат >Остальные работы

Сохрани ссылку в одной из сетей:

Chemistry: Acid-Base Titration Essay, Research Paper

Chemistry: Acid-Base Titration


The objective of this experiment were: a) to review the concept of

simple acid-base reactions; b) to review the stoichiometric calculations

involved in chemical reactions; c) to review the basic lab procedure of a

titration and introduce the student to the concept of a primary standard and the

process of standardization; d) to review the calculations involving chemical

solutions; e) to help the student improve his/her lab technique.


Titration was used to study acid-base neutralization reaction

quantitatively. In acid-base titration experiment, a solution of accurately KHP

concentration was added gradually to another solution of NaOH concentration

until the chemical reaction between the two solutions were completed. 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

indicator that had been added to the acid solution. Indicator was substance that

had distinctly different colors in acidic and basic media. Phenolphthalein was a

common indicator which was colorless in acidic and neutral solutions, but

reddish pink was result in basic solutions. Strong acid (contained H+ ion) and

strong base ( contained OH ) were 100% ionized in water and they were all

strong electrolytes. Procedure:

Part A. Investigating solid NaOH for use as a possible primary standard First of

all, The weight of a weighting paper was measured in analytical balance, then

added two pellets of NaOH and reweighed the total amount of those. At the end of

the lab, reweighed the combination and recorded all results in the lab manual.

Part B. Preparation and standardization of a solution of sodium hydroxide A

clean beaker, burette, three 250ml Erlenmeyer flasks, and florence flask were

rinsed by soap and distilled water. Poured 1.40g of NaOH into florence flask and

added 350ml distilled water, then swirl it and inverted flask five times with

parafilm on the top of it. Next, obtained a vial of KHP from the instructor, and

poured about 0.408g into three different Erlenmeyer flasks by measuring with

analytical balance. Then, filled up about 25ml of distilled water, added 3 drops

of phenolphthalein into it and mixed them well by a glass rod. Labeled all

solutions to prevent mix them up. Before the titration began, the buret should

be rinsed with NaOH solution and recorded the initial buret reading. Titrated

the solutions until the reddish pink color appeared. Recorded the final reading,

and calculated the change of volume.

Part C. Determination of the molar mass of unknown acid Repeated the procedure

above, but this time KHP was replaced with an unknown acidic solution and

concentration. Demanded the number of replaceable hydrogen from the instructor.

Conclusion and Discussion: From the titration results of three trial, the

average of molarity of NaOH is 0.1021 . The percentage deviation in molarity of

NaOH had 0.20% error. The possible error in this experiment were: the error in

taking the buret readings, the error in measuring amount of elements, and the

NaOH was not stable under air.

Загрузить файл

Похожие страницы:

  1. Chemistry

    Реферат >> Остальные работы
    Electron Pair Repulsion Theory: The electron pair repulsion theory states that the electron pairs in the valence energy level of an atom repel each other, and therefore are arranged as far apart as possible. For example, H3O: Due to this theory, different ...
  2. Chemistry Essay Research Paper ChemistryI am chemistry

    Реферат >> Остальные работы
    Chemistry Essay, Research Paper Chemistry I am chemistry. I am mysterious and mature, malodorous, ...
  3. Chemistry In Everyday Life Essay Research Paper

    Реферат >> Остальные работы
    ... Life Essay, Research Paper CHEMISTRY IN EVERYDAY LIFE During laboratory ...
  4. Chemistry Essay Research Paper Rates of Chemical

    Реферат >> Остальные работы
    Chemistry Essay, Research Paper Rates of ...
  5. Chemistry Research Essay Research Paper CHAPTER 32The

    Реферат >> Остальные работы
    Chemistry Research Essay, Research Paper CHAPTER ...

Хочу больше похожих работ...

Generated in 0.0020790100097656