Question
Write a laboratory report on Analysis of a mixture of carbonate and bicarbonate including aim/objectives, apparatus, chemical, procedures, observation, conclusion and results
Answers
GPT-4o mini
# Laboratory Report: Analysis of a Mixture of Carbonate and Bicarbonate
## Aim/Objectives
The aim of this experiment is to analyze a mixture of sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3). The objectives include:
1. To determine the presence and concentration of carbonates and bicarbonates in the mixture.
2. To distinguish between sodium carbonate and sodium bicarbonate using acid-base titration methods.
3. To understand the reaction mechanisms of the carbonates and bicarbonates with acid.
## Apparatus
- Analytical balance
- Beakers (100 mL and 250 mL)
- Erlenmeyer flasks (250 mL)
- Graduated pipette (10 mL)
- Burette
- pH indicator (phenolphthalein and methyl orange)
- Stirring rod
- Funnel
- Distilled water
- Droppers
## Chemicals
- Sodium bicarbonate (NaHCO3)
- Sodium carbonate (Na2CO3)
- Hydrochloric acid (HCl) (0.1 M)
- Carbon dioxide indicator or manual balance for final mass
## Procedures
1. **Preparation of the Sample**:
- Weigh a sample of the mixture (approximately 0.5 g) and record its mass.
2. **Titration with Hydrochloric Acid**:
- In a 250 mL Erlenmeyer flask, dissolve the weighed mixture in about 100 mL of distilled water.
- Add a few drops of phenolphthalein indicator to the solution. This will turn pink if there is carbonate present.
- Prepare the 0.1 M HCl solution in a burette, noting the initial volume.
- Titrate the solution with HCl until the pink color disappears. Record the final volume of HCl dispensed. This indicates the neutralization of carbonate ions (CO3^2-).
- Continue titration after the pink color disappears, until the solution reaches a pH around 4.5-5, indicated by a change in color due to excess acid, which will turn the solution yellow if methyl orange is used.
3. **Calculation of Carbonate and Bicarbonate Content**:
- Using the volume of HCl used in the first stage (for carbonates) and the volume used in the second stage (for bicarbonates), calculate the moles of Na2CO3 and NaHCO3 present using stoichiometric expressions:
- For Na2CO3:
- 1 mole of Na2CO3 reacts with 2 moles of HCl.
- For NaHCO3:
- 1 mole of NaHCO3 reacts with 1 mole of HCl.
## Observation
- The solution initially had a pink hue when phenolphthalein was added, indicating the presence of carbonate ions.
- Upon titration, the pink color disappeared and the solution transitioned to a yellowish color with methyl orange, indicating the formation of carbon dioxide and neutral acidic condition.
### Titration Data (Hypothetical Example):
- Initial volume of HCl: 0.00 mL
- Final volume of HCl after first titration (carbonate reaction): 30.00 mL
- Final volume of HCl after second titration (bicarbonate reaction): 15.00 mL
- Total HCl used for NaHCO3: 15.00 mL (after 30.00 mL for Na2CO3)
## Results
1. Calculate moles of carbonate (Na2CO3):
\[ \text{Moles of } Na2CO3 = \frac{\text{Volume of HCl (L)}}{2} = \frac{30.00 \, \text{mL}}{1000} \div 2 = 0.015 \, \text{mol} \]
2. Calculate moles of bicarbonate (NaHCO3):
\[ \text{Moles of } NaHCO3 = \text{Volume of HCl (L)} = \frac{15.00 \, \text{mL}}{1000} = 0.015 \, \text{mol} \]
3. Total mass of mixture can be calculated as:
\[ \text{Mass of } Na2CO3 = 0.015 \, \text{mol} \times 106 \, \text{g/mol} \approx 1.59 \, \text{g} \]
\[ \text{Mass of } NaHCO3 = 0.015 \, \text{mol} \times 84 \, \text{g/mol} \approx 1.26 \, \text{g} \]
## Conclusion
In conclusion, the analysis successfully differentiated and quantified the amounts of sodium carbonate and sodium bicarbonate in the mixture. The initial pink color of the phenolphthalein indicator confirmed the presence of carbonate ions, and further titration with hydrochloric acid allowed for the determination of both components. The results indicate approximately 1.59 g of sodium carbonate and 1.26 g of sodium bicarbonate in the original mixture, summing up to a total of approximately 2.85 g. The experiment illustrates the effectiveness of titration as a qualitative and quantitative analytical technique in distinguishing between related compounds.
## Aim/Objectives
The aim of this experiment is to analyze a mixture of sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3). The objectives include:
1. To determine the presence and concentration of carbonates and bicarbonates in the mixture.
2. To distinguish between sodium carbonate and sodium bicarbonate using acid-base titration methods.
3. To understand the reaction mechanisms of the carbonates and bicarbonates with acid.
## Apparatus
- Analytical balance
- Beakers (100 mL and 250 mL)
- Erlenmeyer flasks (250 mL)
- Graduated pipette (10 mL)
- Burette
- pH indicator (phenolphthalein and methyl orange)
- Stirring rod
- Funnel
- Distilled water
- Droppers
## Chemicals
- Sodium bicarbonate (NaHCO3)
- Sodium carbonate (Na2CO3)
- Hydrochloric acid (HCl) (0.1 M)
- Carbon dioxide indicator or manual balance for final mass
## Procedures
1. **Preparation of the Sample**:
- Weigh a sample of the mixture (approximately 0.5 g) and record its mass.
2. **Titration with Hydrochloric Acid**:
- In a 250 mL Erlenmeyer flask, dissolve the weighed mixture in about 100 mL of distilled water.
- Add a few drops of phenolphthalein indicator to the solution. This will turn pink if there is carbonate present.
- Prepare the 0.1 M HCl solution in a burette, noting the initial volume.
- Titrate the solution with HCl until the pink color disappears. Record the final volume of HCl dispensed. This indicates the neutralization of carbonate ions (CO3^2-).
- Continue titration after the pink color disappears, until the solution reaches a pH around 4.5-5, indicated by a change in color due to excess acid, which will turn the solution yellow if methyl orange is used.
3. **Calculation of Carbonate and Bicarbonate Content**:
- Using the volume of HCl used in the first stage (for carbonates) and the volume used in the second stage (for bicarbonates), calculate the moles of Na2CO3 and NaHCO3 present using stoichiometric expressions:
- For Na2CO3:
- 1 mole of Na2CO3 reacts with 2 moles of HCl.
- For NaHCO3:
- 1 mole of NaHCO3 reacts with 1 mole of HCl.
## Observation
- The solution initially had a pink hue when phenolphthalein was added, indicating the presence of carbonate ions.
- Upon titration, the pink color disappeared and the solution transitioned to a yellowish color with methyl orange, indicating the formation of carbon dioxide and neutral acidic condition.
### Titration Data (Hypothetical Example):
- Initial volume of HCl: 0.00 mL
- Final volume of HCl after first titration (carbonate reaction): 30.00 mL
- Final volume of HCl after second titration (bicarbonate reaction): 15.00 mL
- Total HCl used for NaHCO3: 15.00 mL (after 30.00 mL for Na2CO3)
## Results
1. Calculate moles of carbonate (Na2CO3):
\[ \text{Moles of } Na2CO3 = \frac{\text{Volume of HCl (L)}}{2} = \frac{30.00 \, \text{mL}}{1000} \div 2 = 0.015 \, \text{mol} \]
2. Calculate moles of bicarbonate (NaHCO3):
\[ \text{Moles of } NaHCO3 = \text{Volume of HCl (L)} = \frac{15.00 \, \text{mL}}{1000} = 0.015 \, \text{mol} \]
3. Total mass of mixture can be calculated as:
\[ \text{Mass of } Na2CO3 = 0.015 \, \text{mol} \times 106 \, \text{g/mol} \approx 1.59 \, \text{g} \]
\[ \text{Mass of } NaHCO3 = 0.015 \, \text{mol} \times 84 \, \text{g/mol} \approx 1.26 \, \text{g} \]
## Conclusion
In conclusion, the analysis successfully differentiated and quantified the amounts of sodium carbonate and sodium bicarbonate in the mixture. The initial pink color of the phenolphthalein indicator confirmed the presence of carbonate ions, and further titration with hydrochloric acid allowed for the determination of both components. The results indicate approximately 1.59 g of sodium carbonate and 1.26 g of sodium bicarbonate in the original mixture, summing up to a total of approximately 2.85 g. The experiment illustrates the effectiveness of titration as a qualitative and quantitative analytical technique in distinguishing between related compounds.