Your session will expire in 15 minutes (at 07:14 PM).
Would you like to keep your session alive?
Your session has expired. For your security, we have logged you out.
Would you like to log in again? SODIUM THIOSULFATE PENTAHYDRATE RG

Sodium Thiosulfate 5-Hydrate

Boiling Point: (°C): 100
CAS Number: 10102-17-7
Density (g/mL): 1.69
Formula: Na2S2O3 • 5H2O
Formula Weight: 248.18
Freezing Point (°C): 48
Shelf Life (months): 12
Solubility: Water
Storage: Green

Please Note: This product is designed for educational and teaching laboratories and no certificate of analysis is available.


Item # Description Unit Price Quantity
WLC94356-06 Sodium Thiosulfate 5-Hydrate, Reagent, Crystal, 500 g Bottle
Each (500g/mol) Retrieving Restricted
WLC94357-06 Sodium Thiosulfate 5-Hydrate, Laboratory, Crystal, 500 g Bottle
Each (500g/mol) Retrieving Restricted
WLC94357-08 Sodium Thiosulfate 5-Hydrate, Laboratory, Crystal, 2.5 kg Bottle
Each (3kg) Retrieving Restricted
restricted This product is marked as restricted and can only be purchased by approved Shipping Accounts. To apply for a shipping account number, click here. If you need further assistance, call Customer Service at 1-800-727-4368 or email


This disposal method is published for your convenience. You MUST have checked with your federal, state, and local regulations before using this method and these methods are only applicable for small laboratory sized quantities.

Use a lab apron, chemical resistant gloves and goggles before following the below method to dispose of hazardous waste.

 1. Add the substance to be disposed of to a large beaker and dissolve it in water. Place the beaker in a fume hood.
 2. Add an equal amount of sodium carbonate to the mixture.
 3. Slowly add a 25% molar excess of bleach to the mixture. Stir.
  a. Add the bleach very slowly as a reaction will occur and produce heat. Keep the reaction under control.
 4. Wait four hours.
 5. Neutralize the resulting mixture with either dilute hydrochloric acid or dilute sodium hydroxide to a pH of about 7.
 6. Pour the final solution down the drain with at least a 20-fold excess of water.

Solution Prep

To prepare a solution, determine the formula weight of the material, the concentration (Molarity) of the solution, and the amount of solution desired in Liters. Once this information has been obtained, use the following formula:
(Formula Weight) x (Concentration) x (Desired Volume) = Number of grams in desired volume of liquid

For a 1 M, 1 L solution:
(Formula Weight) x (1 mol/L) x (1 L) = x g added to 1-L volumetric flask. Dilute to a final volume of 1 L with DI Water.