Acid -base Titration.docx

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Title: Acid-Base Titration Aim: Titration ,Neutralization Apparatus:     

Erlenmeyer flask Beaker Burette Pipette Clamp stand

Materials:  

Hydrochloric acid Sodium hydroxide

Diagram:

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Method: 1. The morality of the sodium hydroxide solution was recorded 2. About 100mL of the sodium hydroxide solution was poured into a clean beaker. 3. A funnel was used to pour 5 mL of the base solution into the burette from the beaker. 4. The funnel was moved around to ensure that the sides of the burette are coated with base . 5. The solution was drained through the stopcock into the waste beaker . The process was repeated with a second 5mL portion of the base . 6. More of the sodium hydroxide solution was poured into the burette until it neared the 50mL mark. 7. 25 mL of the acid solution was pulled into the volumetric pipette and transferred into an Erlenmeyer flask . 8. 2-3 drops of phenolphthalein was added to the acid solution in the Erlenmeyer flask . 9. The flask was placed under the burette and the base solution was added to the Erlenmeyer flask. 10. the flask was swirled while the Base solution was added 11. The final reading of the burette was recorded and the contents of the flask was washed down the drain with water. 12. The burette was refilled with more sodium hydroxide solution and the procedure was repeated.

Observation :

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Result: Trial 1

Trial 2

Trial 3

0

8.3

16.2

8.3

16.2

24

8.3

7.9

7.8

Initial burette volume Final burette volume Volume of base (ml) Volume of base (l) Moles of base

0.0083

0.0079

0.0078

0.00083

0.00079

0.00078

Moles of acid

0.000685

0.000685

0.000685

Volume of acid

0.0250L

0.0250L

0.0250L

Acid Concentration Average Concentration

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Discussion: The concentration of a solution can be found by reacting it with a known volume of standard solution until the reaction is complete .

Moles of acid 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑜𝑙𝑒𝑠 =

𝑚𝑎𝑠𝑠 𝑚𝑜𝑙𝑎𝑟 𝑚𝑎𝑠𝑠

0.0250 = 0.000685moles 36.5 Acid concentration=

𝑚𝑜𝑙 𝑣𝑜𝑙𝑢𝑚𝑒 𝑏𝑎𝑠𝑒 (𝐿) × 𝑀𝑜𝑙𝑎𝑟𝑖𝑡𝑦 𝑜𝑓 𝑏𝑎𝑠𝑒 ( ) = 𝑚𝑜𝑙𝑒𝑠 𝑏𝑎𝑠𝑒 𝑙 Trial 1 0.0083 L × 0.1 = 0.00083 moles Trial 2 0.0079 L × 0.1 = 0.00079 moles Trial 3 0.0078 L × 0.1 = 0.00078 moles 𝑚𝑜𝑙(𝑏𝑎𝑠𝑒) 𝑚𝑜𝑙 𝑎𝑐𝑖𝑑 × = 𝑚𝑜𝑙𝑒𝑠 𝑎𝑐𝑖𝑑 1 𝑚𝑜𝑙 𝑏𝑎𝑠𝑒 𝑚𝑜𝑙𝑒𝑠 𝑎𝑐𝑖𝑑 = 𝑎𝑐𝑖𝑑 𝑚𝑜𝑙𝑎𝑟𝑖𝑡𝑦 𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑎𝑐𝑖𝑑

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Conclusion:

Reflection: Titration is a technique for finding out the concentration of a reactant using an indicator with a known concentration. Indicators, which are standard solutions, are added to the solution, called an analyte, and the change in color of the analyte points to a particular concentration level. The adding of a titrant is performed with the use of a buret. Suitable indicators, also known as titrants, have to be found to determine the concentration of various substances. The real life uses of titration include determining the stage of maturation of cheese and wines, and designing new medicines

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