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Measurement of dissolved co2.

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This document provides instructions for measuring the amount of dissolved carbon dioxide in a water sample through titration with a standard sodium carbonate solution using phenolphthalein as an indicator. The reaction between carbon dioxide and hydroxide or carbonate ions is described. Students are asked to calculate the parts per million of dissolved CO2 in the sample based on their titration results and to answer questions about the oxidation state of carbon in related compounds, equivalent weights of reagents, solubility of CO2, and the role of CO2 as a greenhouse gas.

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SHREE MALLIKARJUN COLLEGE CLASS:SYBSC SAFETY: Refer to MSDS of sodium carbonate, sodium hydroxide and phenolphthalein -Dr. Mithil S. FalDesai Aim: Measurement of dissolved CO2. Chemicals: Sodium carbonate, sodium hydroxide, and phenolphthalein. Apparatus: Standard volumetric flask, pipette, burette, conical flask, beakers, funnel and glass rod. Theory: The amount of dissolved carbon dioxide is determined by titrating the water sample against standardised dilute alkali (<0.02 N). Ideally, sodium carbonate is preferred as it is a primary standard to determine the amount of dissolved CO2. The solubility of CO2 is higher than oxygen in water (1.45 g/L at 25 ◦C). CO2 + (OH)-  (HCO3)- CO2 + (CO3)2- + H2O  2(HCO3)- Procedure: Pipette out 100 mL water sample into a conical flask and add 1-2 drops of phenolphthalein. Rinse and fill the burette with Na2CO3. Titrate the water sample from conical flask and note down the constant reading. Results: i) Amount of dissolved CO2 = ____ppm. . Further reading (available in library) 1) Experiments in Applied Chemistry, S. Rattan, S. K Kataria and Sons. 2) Vogel’s textbook of quantitative chemical analysis, J. Mendham, R. C. Denney, J. D. Barns, M. Thomas, B. Sivasankar, Pearson India Education, 6th Edition. Questions. 1) What is the significance of dissolved CO2? 2) What is the oxidation state of C in CO2, Na2CO3, H2CO3 and (HCO3)- 3) Calculate the equivalent weight of NaOH and Na2CO3. 4) How soda water contains more than 1.45 g/L dissolved CO2? 5) Is CO2 toxic? Explain. 6) Why CO2 is considered a greenhouse gas? 7) Give a qualitative test for CO2.

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Measurement of dissolved co2.

  • 1. SHREE MALLIKARJUN COLLEGE CLASS:SYBSC SAFETY: Refer to MSDS of sodium carbonate, sodium hydroxide and phenolphthalein -Dr. Mithil S. FalDesai Aim: Measurement of dissolved CO2. Chemicals: Sodium carbonate, sodium hydroxide, and phenolphthalein. Apparatus: Standard volumetric flask, pipette, burette, conical flask, beakers, funnel and glass rod. Theory: The amount of dissolved carbon dioxide is determined by titrating the water sample against standardised dilute alkali (<0.02 N). Ideally, sodium carbonate is preferred as it is a primary standard to determine the amount of dissolved CO2. The solubility of CO2 is higher than oxygen in water (1.45 g/L at 25 ◦C). CO2 + (OH)-  (HCO3)- CO2 + (CO3)2- + H2O  2(HCO3)- Procedure: Pipette out 100 mL water sample into a conical flask and add 1-2 drops of phenolphthalein. Rinse and fill the burette with Na2CO3. Titrate the water sample from conical flask and note down the constant reading. Results: i) Amount of dissolved CO2 = ____ppm. . Further reading (available in library) 1) Experiments in Applied Chemistry, S. Rattan, S. K Kataria and Sons. 2) Vogel’s textbook of quantitative chemical analysis, J. Mendham, R. C. Denney, J. D. Barns, M. Thomas, B. Sivasankar, Pearson India Education, 6th Edition. Questions. 1) What is the significance of dissolved CO2? 2) What is the oxidation state of C in CO2, Na2CO3, H2CO3 and (HCO3)- 3) Calculate the equivalent weight of NaOH and Na2CO3. 4) How soda water contains more than 1.45 g/L dissolved CO2? 5) Is CO2 toxic? Explain. 6) Why CO2 is considered a greenhouse gas? 7) Give a qualitative test for CO2.