What is the Difference Between Baking Soda, Washing Soda, and Plaster of Paris?
Baking Soda, Washing Soda, Plaster of Paris is essential in chemistry and helps students understand various practical and theoretical applications related to this topic.
What is Baking Soda, Washing Soda, Plaster of Paris in Chemistry?
The term Baking Soda, Washing Soda, Plaster of Paris refers to three important inorganic compounds widely used in daily life and industry. Baking soda is sodium bicarbonate, washing soda is sodium carbonate decahydrate, and plaster of Paris is calcium sulfate hemihydrate. This concept appears in chapters related to salts, industrial chemistry, and everyday chemistry, making it a foundational part of your chemistry syllabus.
Molecular Formula and Composition
The molecular formulas of these three compounds are given below. Each consists of different ions and hydration states, and all are classified as common salts or chemical compounds.
| Compound | Molecular Formula | IUPAC Name |
|---|---|---|
| Baking Soda | NaHCO3 | Sodium hydrogen carbonate |
| Washing Soda | Na2CO3·10H2O | Sodium carbonate decahydrate |
| Plaster of Paris | CaSO4·½H2O | Calcium sulfate hemihydrate |
Preparation and Synthesis Methods
Baking soda is prepared using the Solvay process, which reacts sodium chloride, ammonia, carbon dioxide, and water to form sodium bicarbonate and ammonium chloride.
Washing soda is produced by heating baking soda (sodium bicarbonate) to obtain sodium carbonate. This sodium carbonate is dissolved in water and recrystallized to give washing soda crystals.
Plaster of Paris is manufactured by heating gypsum (CaSO4·2H2O) at about 150°C, removing part of the water of crystallization and forming calcium sulfate hemihydrate.
Physical Properties of Baking Soda, Washing Soda, Plaster of Paris
- Baking soda: White crystalline powder, slightly salty, soluble in water, alkaline in nature.
- Washing soda: White, granular solid, crystalline, highly soluble, strongly alkaline, slippery.
- Plaster of Paris: Soft, fine white powder, sets quickly with water, forms a hard mass, slightly soluble in water.
Chemical Properties and Reactions
Baking soda decomposes on heating, releasing CO2 and leaving sodium carbonate behind:
NaHCO3 (heat) → Na2CO3 + CO2 + H2O
Washing soda is formed by crystallizing sodium carbonate. It reacts with acids to release CO2.
Plaster of Paris reacts with water to form gypsum:
CaSO4·½H2O + 1½H2O → CaSO4·2H2O
Frequent Related Errors
- Confusing the formulas of baking soda and washing soda.
- Mixing up preparation reactions of plaster of Paris with gypsum.
- Writing wrong water of crystallization in chemical formulas.
- Using the compounds interchangeably in applications.
Uses of Baking Soda, Washing Soda, Plaster of Paris in Real Life
Baking soda is widely used in cooking, antacid medicine, and fire extinguishers. Washing soda is used in cleaning agents, water softening, and textile/dye industries. Plaster of Paris is important in making casts for broken bones, sculptures, decorative articles, and construction work.
Relevance in Competitive Exams
Students preparing for NEET, JEE, and Olympiads should be familiar with Baking Soda, Washing Soda, Plaster of Paris, as it often features in reaction-based and concept-testing questions. Chemical formulas, preparation processes, and differences are frequently asked in CBSE board exams.
Relation with Other Chemistry Concepts
Baking soda, washing soda, and plaster of Paris are closely related to topics such as salts and crystallization and industrial salts, helping students build a conceptual bridge between acids, bases, and real-world applications of salts.
Step-by-Step Reaction Example
1. Start with heating baking soda (NaHCO3):2. Obtain sodium carbonate (washing soda) by dissolving and crystallizing:
3. For plaster of Paris, heat gypsum:
Lab or Experimental Tips
Remember that heating causes baking soda to release CO2 and produce washing soda as a residue. Vedantu educators often use this tip in live sessions to simplify how thermal decomposition reactions can be tested in the lab. When handling plaster of Paris, always add powder to water (and not the reverse) for smoother mixing and safety.
Try This Yourself
- Write the IUPAC name and formula of baking soda, washing soda, and plaster of Paris.
- Show the equation for heating sodium bicarbonate to convert it into washing soda.
- List two household and two industrial uses of each compound.
Final Wrap-Up
We explored Baking Soda, Washing Soda, Plaster of Paris—its structure, properties, reactions, and real-life importance. For more in-depth explanations and exam-prep tips, explore live classes and notes on Vedantu. Accurate knowledge of these compounds lays a strong foundation for advanced chemistry topics and daily science applications.
FAQs on Baking Soda, Washing Soda and Plaster of Paris Explained
1. What are the chemical formulas for baking soda, washing soda, and plaster of Paris?
Baking soda's formula is NaHCO₃ (sodium bicarbonate). Washing soda is Na₂CO₃·10H₂O (sodium carbonate decahydrate). Plaster of Paris is CaSO₄·½H₂O (calcium sulfate hemihydrate).
2. How are baking soda and washing soda different?
Baking soda (NaHCO₃) is a mild base, while washing soda (Na₂CO₃·10H₂O) is a stronger base. Baking soda decomposes upon heating to form washing soda. Key differences include their pH levels and applications; baking soda is used in cooking, while washing soda is used for cleaning.
3. What are the common uses of plaster of Paris in daily life?
Plaster of Paris (CaSO₄·½H₂O) is mainly used for making casts to immobilize fractured bones. It's also used in construction, art, and crafts for molding and casting purposes. Its quick-setting property makes it suitable for various applications.
4. How is washing soda manufactured from baking soda?
Heating baking soda (NaHCO₃) causes it to decompose, releasing carbon dioxide and water, leaving behind washing soda (Na₂CO₃). This is a thermal decomposition reaction. The equation is: 2NaHCO₃ → Na₂CO₃ + H₂O + CO₂
5. Can baking soda dissolve plaster of Paris?
No, baking soda is not effective in dissolving plaster of Paris. Plaster of Paris is relatively insoluble in water and common household solutions.
6. What is the Solvay process?
The Solvay process is an industrial method for producing sodium bicarbonate (baking soda). It involves reacting sodium chloride, carbon dioxide, and ammonia in water. This process efficiently produces baking soda on a large scale.
7. What are the safety precautions when handling Plaster of Paris?
When handling Plaster of Paris, wear a mask to avoid inhaling the powder, which can cause respiratory irritation. Wear gloves to protect your skin. Avoid direct contact with eyes. Dispose of waste properly, as it can harden and clog drains.
8. Explain the chemical reaction involved in the setting of Plaster of Paris.
When water is added to Plaster of Paris (CaSO₄·½H₂O), it undergoes a hydration reaction, forming gypsum (CaSO₄·2H₂O), a hard solid mass. This is an exothermic reaction, meaning it releases heat.
9. What are some industrial uses of washing soda?
Washing soda (sodium carbonate) finds use in various industries, including glass manufacturing, soap and detergent production, water softening, and paper pulp processing. Its strong alkaline nature makes it useful in many chemical processes.
10. How does washing soda act as a water softener?
Washing soda reacts with the calcium and magnesium ions present in hard water, forming insoluble precipitates. These precipitates are removed, leaving the water softer and improving the efficiency of cleaning agents.
11. Describe the difference between anhydrous and hydrated salts.
Anhydrous salts lack water molecules in their crystal structure, while hydrated salts contain water molecules incorporated within their crystal lattice. Washing soda is a hydrated salt, while anhydrous sodium carbonate lacks the water molecules.
12. What is the role of baking soda in baking?
In baking, baking soda acts as a leavening agent. When mixed with an acidic ingredient, it releases carbon dioxide gas, causing the dough or batter to rise, resulting in lighter and fluffier baked goods.
