Method of test for building limes Determination of carbon dioxide content

IS 6932 Part 2 - Scope & Key Specifications for CO₂ Determination in Lime

Scope:

• Specifies the method to determine carbon dioxide (CO₂) content in lime samples.
• CO₂ content is reported as percentage by mass of the sample.

Key Formulas & Procedure Highlights:

• Sample weight: ~2.5 g lime.
• Distilled water: 20–40 ml added to flask.
• Hydrochloric acid: 40 ml added to react with lime.
• Heating: Boil for 30–40 minutes to release CO₂.
• CO₂ absorption: Use absorption tubes (71 and 7) to capture CO₂.
• Mass increase in absorption tubes = CO₂ content.

Summary Table for CO₂ Determination

Reporting:

• CO₂ content = (\frac{\text{Mass increase in absorption tubes}}{\text{Mass of sample}} \times 100%)

Notes:

• Apparatus must be airtight.
• Use distilled water per IS 1070.
• Ensure constant mass of absorption tubes before and after test.

flowchart TD
    A[Weigh Sample (2.5 g)] --> B[Add Distilled Water (20-40 ml)]
    B --> C[Add HCl (40 ml)]
    C --> D[Heat & Boil (30-40 min)]
    D --> E[CO₂ Released]
    E --> F[Pass through Absorption Tubes]
    F --> G[Measure Mass Increase]
    G --> H[Calculate % CO₂ Content]

This concise scope and procedure ensure reliable determination of CO₂ in lime as per IS 6932 (Part II).

Preparation of Sample (IS 6932 Part 2, Clause 2.1 & 3.2)

• Sample Weight: Accurately weigh about 2.5 g of the sample.
• Initial Setup: Transfer sample into flask D; add 20 to 40 ml distilled water.
• Air Purging: Pass air until CO₂ absorption tubes attain constant mass.
• Acid Addition: Introduce 40 ml of dilute hydrochloric acid (1:4 v/v) via funnel C.
• Heating: Heat flask to boil for 30-40 minutes; gases pass through sulphuric acid bubbler.
• Post-Boiling: After 2-3 minutes boiling, remove flame; connect scrubbers A & B.
• Air Flow: Pass air for 20 minutes at moderate rate.
• Final Weighing: Keep absorption tubes at room temperature for 30 minutes, then weigh; mass increase = CO₂ content.

Dilute Hydrochloric Acid Preparation (Clause 3.1.2):

• Mix 1 volume concentrated HCl (sp. gr. 1.16) with 4 volumes water.

Summary Table:

flowchart LR
    A[Weigh 2.5 g Sample] --> B[Add 20-40 ml Distilled Water]
    B --> C[Pass Air Until CO₂ Tubes Constant Mass]
    C --> D[Add 40 ml Dilute HCl]
    D --> E[Heat to Boil 30-40 min]
    E --> F[Remove Flame, Connect Scrubbers]
    F --> G[Pass Air for 20 min]
    G --> H[Rest CO₂ Tubes 30 min at Room Temp]
    H --> I[Weigh Tubes - Mass Increase = CO₂ Content]

IS 6932 Part 2: Apparatus and Reagents for CO₂ Determination in Lime

Key Apparatus & Reagents (Clause 3.1 & 3.2)

• Sample: ~2.5 g lime sample.
• Flask D: Airtight flask with glass stopper, funnel, and condenser.
• Distilled Water: 20-40 ml (per IS:1070-1970).
• Hydrochloric Acid: 40 ml (specification revised).
• Carbon Dioxide Absorption Tubes: Pre-weighed and maintained at constant mass.
• Sulphuric Acid Bubbler: For gas passage.
• Scrubbers A & B: For air purification.

Procedure Summary (Clause 3.2)

1. Weigh sample → add distilled water in flask D.
2. Assemble airtight apparatus with stopper, funnel, condenser.
3. Pass air until CO₂ absorption tubes reach constant weight.
4. Introduce HCl → heat to generate CO₂ → gases pass through sulphuric acid bubbler.
5. Boil for 30-40 min, then air passed for 20 min.
6. Cool absorption tubes at room temp for 30 min → weigh.
7. Increase in tube mass = CO₂ content.

Reporting (Clause 3.3)

• CO₂ content (%) =
  [ \frac{\text{Increase in mass of absorption tubes (g)}}{\text{Mass of sample (g)}} \times 100 ]

Summary Table

flowchart LR
    A[Weigh Sample (~2.5g)] --> B[Add 20-40 ml Distilled Water]
    B --> C[Assemble Airtight Flask D]
    C --> D[Pass Air until CO₂ Tubes Stable]
    D --> E[Add 40 ml H

IS 6932 Part 2: Determination of Carbon Dioxide Content in Building Lime

Key Procedure (Clause 3.2)

• Weigh ~2.5 g lime sample; add 20–40 ml distilled water in flask D.
• Assemble airtight apparatus with stopper, funnel, condenser.
• Pass air until absorption tubes 71 and 7 reach constant mass.
• Close stopcock, insert weighed CO₂ absorption tubes.
• Add 40 ml HCl via funnel C; heat to release CO₂ gas.
• Gas passes through sulfuric acid bubbler; boil for 30–40 min.
• After boiling, remove heat; connect flask to scrubbers A & B.
• Pass air for 20 min at moderate rate.
• Keep absorption tubes at room temp 30 min; weigh tubes again.
• Increase in mass = CO₂ content in sample.

Important Specifications

• Use distilled water as per IS 1070:1992.
• Use hydrochloric acid of specified concentration.
• Follow rounding rules per IS 2:1960.
• Refer to IS 712:1984 for building lime specifications.

Formula for CO₂ Content Calculation

[ \text{CO}_2 % = \frac{\text{Increase in mass of absorption tubes (g)}}{\text{Mass of lime sample (g)}} \times 100 ]

Summary Diagram of Apparatus Flow

flowchart LR
    A[Sample + Distilled Water in Flask D] --> B[Add HCl & Heat]
    B --> C[CO₂ Gas Released]
    C --> D[Sulfuric Acid Bubbler]
    D --> E[CO₂ Absorption Tubes (71 & 7)]
    E --> F[Scrubbers A & B]
    F --> G[Air Outlet]

This method ensures accurate quantification of CO₂ content by gravimetric increase in absorption tubes after acid digestion and gas absorption.

IS 6932 Part 2 (1973) — Test Procedure for Carbon Dioxide Content in Lime

Key Specifications & Procedure:

• Sample Preparation:
  Follow IS 712:1973 Clause 7.2 for preparing the lime sample.

• Apparatus Setup:
  Use flask D with a glass stopper, funnel, condenser, and carbon dioxide absorption tubes (71 and 7). Ensure air-tight assembly (Fig. 1 in code).

• Test Steps:

  1. Weigh ~2.5 g of sample; place in flask D.
  2. Add 20–40 ml distilled water.
  3. Pass air until absorption tubes reach constant mass.
  4. Close stopcock S; insert weighed absorption tubes.
  5. Add 40 ml hydrochloric acid via funnel C.
  6. Heat flask to boil for 30–40 minutes; gases pass through sulphuric acid bubbler.
  7. After boiling 2–3 min, remove heat; connect scrubbers A & B.
  8. Pass air for 20 min at moderate rate.
  9. Keep absorption tubes at room temperature 30 min; weigh again.

• Calculation:
  [ \text{CO}_2 % = \frac{\text{Increase in mass of absorption tubes}}{\text{Mass of sample}} \times 100 ]

• Reporting:
  Carbon dioxide content is reported as % by mass of sample (Clause 3.3).

Summary Table:

flowchart TD
    A[Weigh Sample (~2.5 g)] --> B[Add Distilled Water (20-40 ml)]
    B --> C[Insert Absorption Tubes & Pass Air]
    C --> D[Add HCl (40 ml)

IS 6932 Part 2 (1973) - Calculation & Expression of Results for CO₂ Content

• Reporting:
  Carbon dioxide content is reported as percentage by mass of the sample (Clause 3.3).

• Calculation Formula:
  [ \text{CO}_2% = \frac{\text{Increase in mass of absorption tubes (g)}}{\text{Mass of sample taken (g)}} \times 100 ]

• Procedure Summary (Clause 3.2):

  1. Weigh ~2.5 g sample.
  2. Add 20–40 ml distilled water in flask.
  3. Pass air to attain constant mass of CO₂ absorption tubes.
  4. Introduce 40 ml HCl, heat to release CO₂ gas.
  5. Pass gases through absorption tubes, weigh tubes after absorption.
  6. Mass increase = CO₂ absorbed.

• Key Specification:
  Use distilled water as per IS 1070-1970.

Visual summary of process:

flowchart LR
    A[Weigh sample (~2.5g)] --> B[Add distilled water (20-40ml)]
    B --> C[Pass air until absorption tubes stable]
    C --> D[Add 40 ml HCl, heat to release CO₂]
    D --> E[CO₂ passes through absorption tubes]
    E --> F[Weigh absorption tubes; mass increase = CO₂ content]

This ensures precise quantification of CO₂ as % mass of the lime sample.

IS 6932 Part 2 (1973) - Reporting of Test Results

• Clause 3.3: The carbon dioxide (CO₂) content in the lime sample shall be reported as a percentage of the mass of the sample taken.

Key Points:

• Sample Preparation: Follow IS 712:1973 Clause 7.2 for preparing the sample.
• Test Method: Determination of CO₂ content as per IS 6932 Part II.
• Report Format: Express CO₂ content as % by mass of the tested lime sample.

Summary Table for Reporting:

Additional Notes:

• Ensure accurate weighing of the lime sample.
• Use standard apparatus and reagents as per Clause 3.1 of IS 6932 Part II.
• Report values clearly to maintain consistency and reliability in quality control.

flowchart LR
    A[Sample Preparation (IS 712:7.2)] --> B[Test for CO₂ Content (IS 6932 Part II)]
    B --> C[Calculate % CO₂ by mass]
    C --> D[Report Results as % CO₂]

This ensures uniformity in reporting and facilitates comparison across batches or suppliers.

IS 6932 Part 2 (1973) — References & Related Standards Summary

Scope:

• Method for determination of carbon dioxide (CO₂) content in building limes.
• CO₂ content reported as percentage by mass of the sample (Clause 3.3).

Key Related Standards (Amendment May 2010)

Reporting Format (Clause 3.3)

• CO₂ content (%) = (Mass of CO₂ / Mass of sample) × 100
• Round off results as per IS 2:1960.

Offices for Reference & Purchase

• Headquarters: Manak Bhavan, New Delhi
• Regional Offices: Delhi, Calcutta, Chandigarh, Madras, Bombay
• Branch Offices: Ahmedabad, Bangalore, Bhopal, Bhubaneshwar, Guwahati, Hyderabad, Jaipur, Kanpur, Patna, Trivandrum
• Inspection & Sales Offices: Nagpur, Pune, Calcutta, Bombay, Bangalore

flowchart LR
  A[Sample Collection] --> B[Chemical Analysis]
  B --> C[Calculate CO₂ Content]
  C --> D[Report as % mass]
  D --> E[Round off per IS 2:1960]
  E --> F[Final Test Report]

Summary: Use IS 6932 Part 2 for CO₂ determination in building lime, report results as % mass, and refer to updated related standards IS 712:1984, IS 1070:1992, IS 265:1993, and IS 2:1960 for specifications and rounding rules.

IS 6932 (Part 2) - Amendments and Revisions Summary

Scope:

• Covers method of test for determination of carbon dioxide (CO₂) content in building limes.

Key Amendments (May 2010)

Reporting of Test Results (Clause 3.3)

• CO₂ content shall be reported as % by mass of the sample.

Important Specifications Referenced

Summary Diagram: Amendment Flow

flowchart LR
    A[IS 6932 (Part II) - 1973] --> B[Amendment May 2010]
    B --> C[IS 712:1984 (Building Limes)]
    B --> D[IS 1070:1992 (Reagent Water)]
    B --> E[IS 265:1993 (Quicklime)]
    B --> F[IS 2:1960 (Rounding Rules)]

For detailed test procedures and formulae, refer to the updated IS 6932 (Part II) and referenced IS codes.