Calcium Sulphate Hemihydrate (CaSO₄·½H₂O) – LR Grade, 5kg

Calcium Sulphate ½H₂O, commonly known as Plaster of Paris, is a high quality Laboratory Reagent (LR) grade material supplied in a 5kg pack, ideal for use in educational science laboratories and classroom demonstrations. This finely powdered calcium salt is widely used in schools due to its clear setting reaction and strong links to core chemistry curriculum topics.

The compound has a CAS Number of 10034‑76‑1 and no UN number assigned (UN: NR). Calcium sulphate hemihydrate reacts readily with water to form gypsum, producing a visible and measurable exothermic setting process. These properties make it particularly suitable for practical investigations and cross‑curricular STEM activities.

Supplied clearly labelled and designed for safe storage in school prep rooms, this product supports repeated classroom use and reliable experimental outcomes when handled in accordance with standard laboratory safety guidelines.

Key Features

• Calcium sulphate hemihydrate (Plaster of Paris)
• LR (Laboratory Reagent) grade
• CAS No: 10034‑76‑1
• UN No: NR
• Pack size: 5kg
• Fine white powder that sets when mixed with water
• Ideal for repeated classroom demonstrations and experiments
• Clearly labelled for safe handling and storage

Ideal for School Science Lessons

Calcium Sulphate ½H₂O is highly suitable for KS3, GCSE, and A Level science lessons, supporting both chemistry and materials‑based investigations. Its setting reaction provides strong visual and practical engagement for students.

• Demonstrating reversible and irreversible chemical changes
• Teaching about hydrated compounds and water of crystallisation
• Investigating exothermic reactions
• Supporting practical work on materials and properties
• Linking chemistry to real‑world applications in construction and manufacturing

Reliable, versatile, and curriculum aligned, Calcium Sulphate Hemihydrate (Plaster of Paris) is an essential material for hands‑on science teaching, helping students connect theoretical knowledge with observable chemical processes in a safe and engaging way.