- What it is. This mercuric nitrate solution is a 0.01 N volumetric titrant, supplied in a 1 L size, used to determine chloride in water and wastewater by mercurimetric titration. It is a clear, colorless, acidified aqueous solution.
- How the titration works. Mercuric ions combine with chloride to form soluble but only slightly dissociated mercuric chloride. Once all chloride has reacted, excess mercuric ion forms a blue-violet complex with diphenylcarbazone indicator, marking the endpoint.
- Why the endpoint is easier to see. Compared with the silver nitrate method, the mercuric nitrate endpoint is sharper and easier to detect, and the method suits lower chloride levels. Standard Methods 4500-Cl⁻ C specifies a pH range of 2.3 to 2.8, with xylenol orange or bromophenol blue as the indicator showing the correct pH.
- What 0.01 N means. Mercury(II) carries two charges, so 0.01 N mercuric nitrate is 0.005 M. Each milliliter reacts with 0.01 milliequivalent of chloride, equal to 0.3545 mg of chloride (calculated), which converts titration volume directly into chloride content.
- Interferences. Bromide and iodide titrate along with chloride. Chromate, ferric, and sulfite ions interfere above about 10 mg/L, so samples high in those species need pretreatment or an alternative method.
- Calculating results. Chloride (mg/L) equals (titrant volume minus blank volume) multiplied by normality and 35,450, then divided by the sample volume in milliliters. With 0.01 N titrant, each milliliter corresponds to 0.3545 mg of chloride.
- Standardization. Standardize mercuric nitrate against a standard sodium chloride solution using diphenylcarbazone indicator, or against standard thiocyanate with ferric alum indicator, and restandardize periodically for regulated work.
- Mercury hazards and waste. Mercury compounds are toxic and harmful to aquatic life. Wear gloves and eye protection, avoid ingestion and skin contact, and collect all titration waste and rinses for hazardous waste disposal. Never pour mercury-containing solutions down the drain.
- Where it is used. Mercuric nitrate titrant is used to determine chloride in drinking water, wastewater, boiler and cooling water, and process water in labs whose permits or methods specify the mercurimetric procedure. Many labs use silver nitrate where mercury use can be avoided.
Technical Specifications
| Chemical Name | Mercury(II) nitrate, aqueous volumetric solution |
| CAS Numbers | 7783-34-8 (mercuric nitrate monohydrate); 7697-37-2 (nitric acid, if present); 7732-18-5 (water). Confirm on SDS |
| Synonyms | Mercuric nitrate, mercury(II) nitrate |
| Formula (active) | Hg(NO3)2·H2O |
| Formula Weight (monohydrate) | 342.62 g/mol |
| Equivalent Weight | 171.31 (molar = 2 x normal) |
| Concentration | 0.01 N (0.005 M) |
| Mercuric Nitrate Content | About 1.713 g/L monohydrate (calculated) |
| Chloride Equivalence | 1.00 mL = 0.3545 mg Cl⁻ (calculated) |
| Indicator | Diphenylcarbazone (with xylene cyanol FF or bromophenol blue) |
| Titration pH | 2.3 to 2.8 (Standard Methods 4500-Cl⁻ C) |
| Interferences | Bromide, iodide; chromate, ferric, sulfite above about 10 mg/L |
| Exposure Limit (mercury compounds, as Hg) | OSHA PEL 0.1 mg/m³ ceiling |
| Package Size | 1 L |
Applications / Common Uses
- Chloride in drinking water: Determines chloride by mercurimetric titration.
- Wastewater testing: Measures chloride for permit reporting.
- Boiler and cooling water: Monitors chloride in industrial water systems.
- Process water QC: Checks chloride in production water.
- Method-specified analysis: Supplies titrant where methods name mercuric nitrate.
Storage, Handling & Shipping
Caution: Mercuric nitrate solution contains mercury, which is toxic and harmful to aquatic life. Avoid skin contact and ingestion; wear gloves and eye protection, and collect all waste for hazardous waste disposal.
Store tightly closed at room temperature in a secure, well-ventilated area, segregated from incompatible materials and food. Label storage areas for mercury compounds, and keep a mercury spill kit available.
- Incompatible materials: Reducing agents, strong bases, and reactive metals.
- Exposure limit (mercury compounds, as Hg): OSHA PEL 0.1 mg/m³ ceiling.
- Spill response: Contain with absorbent and collect for mercury hazardous waste disposal. Do not wash to drain.
- First aid: Skin: wash with soap and water. Eyes: rinse for several minutes. Ingestion: seek immediate medical attention.
Related Categories & Services
- Shop Buffers, Standards & Solutions for related products in this category.
- Explore Inorganic Chemicals and ACS Grade Laboratory Chemicals.
- Vendor Managed Inventory (VMI) Program: Lab Pro can stock, track, and replenish this item on site so it never runs out. Contact info@labproinc.com or 888-452-2776 to set up a VMI assessment.
Related Articles
FAQs
How does the mercuric nitrate chloride titration work?
Mercuric ions combine with chloride to form soluble, slightly dissociated mercuric chloride. When all chloride has reacted, excess mercuric ion forms a blue-violet complex with diphenylcarbazone indicator. Multiply the titrant volume by its chloride equivalence to get the sample's chloride content. Run a reagent blank alongside samples.
How much chloride does 1 mL of 0.01 N mercuric nitrate titrate?
One milliliter of 0.01 N mercuric nitrate reacts with 0.01 milliequivalent of chloride, which is 0.3545 mg. Divide the milligrams of chloride found by the sample volume in liters to report mg/L, using the standardized normality if it differs from 0.01 N. Subtract the blank volume first.
What pH is needed for the mercuric nitrate method?
Standard Methods 4500-Cl⁻ C specifies a titration pH of 2.3 to 2.8. The method includes a pH indicator, such as xylene cyanol FF or bromophenol blue, with the diphenylcarbazone so the analyst can confirm the sample is in the correct range before titrating. Results run high below this range and low above it.
Why use mercuric nitrate instead of silver nitrate?
The mercuric nitrate endpoint is sharper and easier to see, and the method works well at lower chloride levels. However, mercury is more toxic and harder to dispose of, so many labs use silver nitrate unless their method or permit specifies the mercurimetric procedure. Check which method your permit names.
How should mercuric nitrate waste be handled?
Collect all titration waste, rinses, and spills in a labeled container for mercury-containing hazardous waste, and arrange disposal through a licensed contractor. Never pour mercury solutions down the drain, and follow local, state, and federal regulations for mercury waste. Keep mercury waste separate from other waste streams so it can be handled and documented correctly.
Related Products
