Specification of Sodium Thiosulphate (Anhydrous) 

Product  

Sodium Thiosulphate (anhydrous)

CAS NO. 

7772-98-7

Formula

Na2O3S2

Mol Wt. 

158.10

PHYSICAL PROPERTIES

Appearance

Clear to white Crystalline free flowing powder

Absolute Density at 25°C (g/ml)

>99 %

Bulk Density (lbs/ft) 

68

Solubility in Water at 0°C (%)

42.7

CHEMICAL PROPERTIES

Na2S2O₃

99.0% min

Na2SO3

0.5% max

NaOH 

0.01% max

pH of 10% Soln 

7.5 - 8.5

Sulphides (Na2S )

20 ppm max

Iron (fe), % by wt 

15 ppm max

Heavy Metals (as Pb) % by wt

5 ppm max

Packing

Paper bag with inner liner,25kg net

THIS INFORMATION IS BASED ON OUR PRESENT STATE OF KNOWLEDGE AND IS INTENDED TO DESCRIBE OUR PRODUCT FROM THE POINT OF VIEW OF TECHNICAL SPECIFICATION. IT SHOULD NOT, THEREFORE, BE CONSTRUED AS GUARANTEE SPECIFIC PROPERTIES.