Question
Write a comprehensive laboratory report on preparation and standardization of 0.1M NaOH and 0.1M HCl including the apparatus/chemical, aid/objective, procedure, observation, result and conclusion
Answers
GPT-4o mini
# Laboratory Report on the Preparation and Standardization of 0.1M NaOH and 0.1M HCl
## Objective
The objective of this experiment is to prepare 0.1M sodium hydroxide (NaOH) and hydrochloric acid (HCl) solutions and to standardize these solutions using a primary standard, potassium hydrogen phthalate (KHP) for NaOH and sodium carbonate (Na2CO3) for HCl.
## Apparatus and Chemicals
### Apparatus
1. Analytical balance
2. Volumetric flask (1 L)
3. Graduated pipette (25 mL)
4. Burette (50 mL)
5. Erlenmeyer flask (250 mL)
6. Conical flask
7. Glass stirring rod
8. White tile
9. pH meter or indicator solution (phenolphthalein for NaOH and methyl orange for HCl)
### Chemicals
1. Sodium hydroxide (NaOH) - solid
2. Hydrochloric acid (HCl) - concentrated
3. Potassium hydrogen phthalate (KHP) - primary standard
4. Sodium carbonate (Na2CO3) - primary standard
5. Distilled water
## Procedure
### Preparation of 0.1M NaOH
1. **Calculation of Mass:**
- The molar mass of NaOH = 40.00 g/mol.
- For 0.1M solution, prepare 1 L (1000 mL) using the formula:
\[
\text{mass (g)} = \text{molarity (mol/L)} \times \text{molar mass (g/mol)} \times \text{volume (L)} = 0.1 \times 40.00 \times 1 = 4.00 \text{ g}
\]
2. **Weighing NaOH:**
- Accurately weigh 4.00 g of solid NaOH using an analytical balance.
3. **Dissolving NaOH:**
- Transfer the NaOH into a volumetric flask and dissolve in a small amount of distilled water.
- Swirl to ensure complete dissolution and then add distilled water to the mark (1 L).
### Standardization of 0.1M NaOH
1. **Preparing KHP Sample:**
- Weigh approximately 0.4 g of KHP (molar mass = 204.22 g/mol).
2. **Dissolving KHP:**
- Dissolve the KHP in a 250 mL Erlenmeyer flask with about 100 mL of distilled water.
3. **Adding Indicator:**
- Add 2-3 drops of phenolphthalein to the KHP solution.
4. **Titration:**
- Fill the burette with 0.1M NaOH.
- Titrate the KHP solution with NaOH, swirling the flask constantly until a faint pink endpoint is observed.
5. **Recording Volume:**
- Record the initial and final burette readings to calculate the volume of NaOH used.
### Preparation of 0.1M HCl
1. **Calculating Volume of Concentrated HCl:**
- The molarity of concentrated HCl is typically around 12M. Thus, to prepare a 0.1M solution:
\[
\text{Volume of concentrated HCl (mL)} = \text{desired molarity (M)} \times \text{desired volume (L)} \div \text{concentration (M)} = 0.1 \times 1 \div 12 = 0.00833 \text{ L or 8.33 mL}
\]
2. **Preparation:**
- Carefully measure 8.33 mL of concentrated HCl using a graduated pipette and dilute in a volumetric flask to 1 L with distilled water.
### Standardization of 0.1M HCl
1. **Preparing Sodium Carbonate Sample:**
- Weigh approximately 1.06 g of Na2CO3 (molar mass = 105.99 g/mol).
2. **Dissolving Na2CO3:**
- Dissolve in 250 mL of distilled water in an Erlenmeyer flask.
3. **Adding Indicator:**
- Add 2-3 drops of methyl orange to the Na2CO3 solution.
4. **Titration:**
- Fill the burette with 0.1M HCl.
- Titrate the Na2CO3 solution with HCl, swirling until the solution changes color from yellow to pink-orange.
5. **Recording Volume:**
- Note the volume of HCl used to reach the endpoint.
## Observations
- **NaOH Titration:**
- The endpoint is reached when a faint pink color persists, indicating that all KHP has reacted with NaOH.
- **HCl Titration:**
- The solution changes color from yellow to a light pink, indicating that Na2CO3 has been neutralized.
## Results
- **NaOH Standardization:**
- Volume of 0.1M NaOH used (average titration result): V mL
- The exact concentration can be calculated using the moles of KHP and the volume of NaOH used.
- **HCl Standardization:**
- Volume of 0.1M HCl used (average titration result): V' mL
- The exact concentration can be computed using the moles of Na2CO3 and the volume of HCl used.
## Conclusion
The preparation and standardization of 0.1M NaOH and 0.1M HCl were successfully accomplished in this experiment. The NaOH solution was standardized using KHP, and the HCl solution was standardized using Na2CO3. Careful measurements and observations ensured accurate titration results. The importance of accurate standardization of reagents is crucial for high precision in various applications in analytical chemistry.
## Objective
The objective of this experiment is to prepare 0.1M sodium hydroxide (NaOH) and hydrochloric acid (HCl) solutions and to standardize these solutions using a primary standard, potassium hydrogen phthalate (KHP) for NaOH and sodium carbonate (Na2CO3) for HCl.
## Apparatus and Chemicals
### Apparatus
1. Analytical balance
2. Volumetric flask (1 L)
3. Graduated pipette (25 mL)
4. Burette (50 mL)
5. Erlenmeyer flask (250 mL)
6. Conical flask
7. Glass stirring rod
8. White tile
9. pH meter or indicator solution (phenolphthalein for NaOH and methyl orange for HCl)
### Chemicals
1. Sodium hydroxide (NaOH) - solid
2. Hydrochloric acid (HCl) - concentrated
3. Potassium hydrogen phthalate (KHP) - primary standard
4. Sodium carbonate (Na2CO3) - primary standard
5. Distilled water
## Procedure
### Preparation of 0.1M NaOH
1. **Calculation of Mass:**
- The molar mass of NaOH = 40.00 g/mol.
- For 0.1M solution, prepare 1 L (1000 mL) using the formula:
\[
\text{mass (g)} = \text{molarity (mol/L)} \times \text{molar mass (g/mol)} \times \text{volume (L)} = 0.1 \times 40.00 \times 1 = 4.00 \text{ g}
\]
2. **Weighing NaOH:**
- Accurately weigh 4.00 g of solid NaOH using an analytical balance.
3. **Dissolving NaOH:**
- Transfer the NaOH into a volumetric flask and dissolve in a small amount of distilled water.
- Swirl to ensure complete dissolution and then add distilled water to the mark (1 L).
### Standardization of 0.1M NaOH
1. **Preparing KHP Sample:**
- Weigh approximately 0.4 g of KHP (molar mass = 204.22 g/mol).
2. **Dissolving KHP:**
- Dissolve the KHP in a 250 mL Erlenmeyer flask with about 100 mL of distilled water.
3. **Adding Indicator:**
- Add 2-3 drops of phenolphthalein to the KHP solution.
4. **Titration:**
- Fill the burette with 0.1M NaOH.
- Titrate the KHP solution with NaOH, swirling the flask constantly until a faint pink endpoint is observed.
5. **Recording Volume:**
- Record the initial and final burette readings to calculate the volume of NaOH used.
### Preparation of 0.1M HCl
1. **Calculating Volume of Concentrated HCl:**
- The molarity of concentrated HCl is typically around 12M. Thus, to prepare a 0.1M solution:
\[
\text{Volume of concentrated HCl (mL)} = \text{desired molarity (M)} \times \text{desired volume (L)} \div \text{concentration (M)} = 0.1 \times 1 \div 12 = 0.00833 \text{ L or 8.33 mL}
\]
2. **Preparation:**
- Carefully measure 8.33 mL of concentrated HCl using a graduated pipette and dilute in a volumetric flask to 1 L with distilled water.
### Standardization of 0.1M HCl
1. **Preparing Sodium Carbonate Sample:**
- Weigh approximately 1.06 g of Na2CO3 (molar mass = 105.99 g/mol).
2. **Dissolving Na2CO3:**
- Dissolve in 250 mL of distilled water in an Erlenmeyer flask.
3. **Adding Indicator:**
- Add 2-3 drops of methyl orange to the Na2CO3 solution.
4. **Titration:**
- Fill the burette with 0.1M HCl.
- Titrate the Na2CO3 solution with HCl, swirling until the solution changes color from yellow to pink-orange.
5. **Recording Volume:**
- Note the volume of HCl used to reach the endpoint.
## Observations
- **NaOH Titration:**
- The endpoint is reached when a faint pink color persists, indicating that all KHP has reacted with NaOH.
- **HCl Titration:**
- The solution changes color from yellow to a light pink, indicating that Na2CO3 has been neutralized.
## Results
- **NaOH Standardization:**
- Volume of 0.1M NaOH used (average titration result): V mL
- The exact concentration can be calculated using the moles of KHP and the volume of NaOH used.
- **HCl Standardization:**
- Volume of 0.1M HCl used (average titration result): V' mL
- The exact concentration can be computed using the moles of Na2CO3 and the volume of HCl used.
## Conclusion
The preparation and standardization of 0.1M NaOH and 0.1M HCl were successfully accomplished in this experiment. The NaOH solution was standardized using KHP, and the HCl solution was standardized using Na2CO3. Careful measurements and observations ensured accurate titration results. The importance of accurate standardization of reagents is crucial for high precision in various applications in analytical chemistry.