Sodium Thiosulphate Pentahydrate (Na₂S₂O₃·5H₂O) – 3kg, Laboratory Reagent Grade

Sodium Thiosulphate Pentahydrate is a high‑purity Laboratory Reagent (LR) grade chemical supplied in a generous 3kg pack, making it ideal for routine use in school laboratories, colleges, and educational science departments. Known for its excellent stability and solubility in water, sodium thiosulphate is a widely used and trusted compound in chemistry teaching and practical experiments.

With the chemical formula Na₂S₂O₃·5H₂O and CAS number 10102‑17‑7, this compound is not classified as dangerous for transport (UN Number: Not Regulated), making it straightforward to store and handle when used in line with standard laboratory guidelines. Its consistent quality ensures reliable results for demonstrations, investigations, and student experiments.

Supplied in solid crystalline form, Sodium Thiosulphate Pentahydrate is commonly used as a reducing agent and is particularly well known for its role in reaction‑rate experiments and photographic chemistry. The 3kg size is well‑suited to busy teaching environments where repeated practical work is scheduled throughout the academic year.

Key Features

• Sodium Thiosulphate Pentahydrate (Na₂S₂O₃·5H₂O)
• Laboratory Reagent (LR) grade for educational use
• 3kg pack size – ideal for schools and colleges
• CAS No: 10102‑17‑7
• UN Number: Not Regulated
• Stable, water‑soluble crystalline solid
• Suitable for repeated classroom and laboratory experiments

Ideal for School Science Lessons

Sodium Thiosulphate Pentahydrate is a staple chemical for KS3, GCSE, and A‑Level chemistry lessons. It is most famously used in the classic “disappearing cross” reaction‑rate experiment, where students investigate how concentration or temperature affects the speed of a chemical reaction.

• Demonstrating rates of reaction in GCSE and A‑Level chemistry
• Supporting investigations into reaction speed and collision theory
• Use as a reducing agent in introductory redox chemistry
• Safe, controlled practical work under teacher supervision
• Reliable preparation of solutions for repeatable classroom experiments

A reliable and versatile laboratory chemical, Sodium Thiosulphate Pentahydrate supports clear, engaging science teaching while helping students build practical skills and a deeper understanding of core chemical concepts.