write an equation to show the reaction between plaster of paris and water
Write an equation to show the reaction between plaster of paris and water
Answer:
Plaster of Paris, chemically known as calcium sulfate hemihydrate, reacts with water to form gypsum. The chemical formula for plaster of Paris is \text{CaSO}_{4} \cdot \frac{1}{2} \text{H}_2 \text{O}, and the chemical formula for gypsum is
\text{CaSO}_{4} \cdot 2 \text{H}_2 \text{O}.
When plaster of Paris is mixed with water, it undergoes a hydration reaction to form gypsum. The chemical equation for this reaction is as follows:
\text{CaSO}_{4} \cdot \frac{1}{2} \text{H}_2 \text{O} + \frac{3}{2} \text{H}_2 \text{O} \rightarrow \text{CaSO}_{4} \cdot 2 \text{H}_2 \text{O}
Breaking it down:
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Reactants:
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Plaster of Paris (Calcium sulfate hemihydrate):
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\text{CaSO}_{4} \cdot \frac{1}{2} \text{H}_2 \text{O}
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Water: \frac{3}{2} \text{H}_2 \text{O}
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Products:
- Gypsum (Calcium sulfate dihydrate): \text{CaSO}_{4} \cdot 2 \text{H}_2 \text{O}
Explanation:
- Plaster of Paris is essentially dehydrated gypsum. When it is mixed with water, it rehydrates and forms gypsum.
- This reaction is exothermic, meaning it releases heat.
- The reformed gypsum sets and hardens, making it useful in various applications like making casts for broken bones, sculptures, and molds.
Final Answer:
The chemical equation showing the reaction between plaster of Paris and water is:
\text{CaSO}_{4} \cdot \frac{1}{2} \text{H}_2 \text{O} + \frac{3}{2} \text{H}_2 \text{O} \rightarrow \text{CaSO}_{4} \cdot 2 \text{H}_2 \text{O}