What is the pH range for Type 3 reagent water?

What is the pH range for Type 3 reagent water?

• A. Not specified
• B. 2.0-4.0
• C. 5.0-8.0
• D. 9.0-12.0

Answer: (C)

The pH range for Type 3 reagent water is kept near neutral for general, non-critical lab tasks. This avoids introducing strong acidity or basicity that could alter reagents, affect measurements, or cause corrosion of glassware and equipment. Water with a pH between 5.0 and 8.0 is broad enough to accommodate natural drift due to dissolved CO2 and temperature, while still ensuring compatibility with most routine assays and procedures. Values in the acidic range (2.0–4.0) could interfere with samples and materials, and strongly basic values (9.0–12.0) could likewise cause interference. Therefore, 5.0–8.0 is the appropriate range.

The pH range for Type 3 reagent water is kept near neutral for general, non-critical lab tasks. This avoids introducing strong acidity or basicity that could alter reagents, affect measurements, or cause corrosion of glassware and equipment. Water with a pH between 5.0 and 8.0 is broad enough to accommodate natural drift due to dissolved CO2 and temperature, while still ensuring compatibility with most routine assays and procedures. Values in the acidic range (2.0–4.0) could interfere with samples and materials, and strongly basic values (9.0–12.0) could likewise cause interference. Therefore, 5.0–8.0 is the appropriate range.