Evaporating Dish: Uses, Types, and Complete Guide

What is an Evaporating Dish?

An evaporating dish is a small laboratory tool made for heating liquids to evaporate the solvent, leaving behind a concentrated substance or solid residue. If you’ve ever worked in a lab, you’ve likely used one. Think of it as the shallow, heat-loving cousin of the beaker.

Importance of Evaporating Dishes in Laboratories

These dishes are essential in any chemistry setup. Whether it’s for creating crystals, concentrating solutions, or performing qualitative analysis, they’re the go-to tool.

Design and Structure

Material Composition

Evaporating dishes come in various materials, and each type has its unique benefits.

Porcelain

The most common type—resistant to chemicals and can withstand high heat. Ideal for general use.

Glass

Less common but useful for when visibility is crucial. However, they aren’t as heat-resistant as porcelain.

Metal

Used for specific applications where extremely high temperatures are involved, like in metallurgy.

Shape and Size Variations

They typically have a shallow, flat bottom and a spout for pouring. Sizes range from 30 ml to 250 ml or more, depending on the need.

Functions and Applications

Main Use: Evaporation of Liquids

As the name suggests, the primary job is evaporation—especially of water or volatile solvents.

Use in Chemistry Experiments

Used to dry a substance, separate mixtures, or even perform simple reactions under heat.

Use in Educational Laboratories

In schools and colleges, students use evaporating dishes to observe chemical reactions and crystallization.

Types of Evaporating Dishes

Porcelain Evaporating Dishes

Most widely used. Great heat resistance and chemically inert.

Glass Evaporating Dishes

Used when observation is important—ideal for color reactions and transparent liquids.

Quartz Evaporating Dishes

Highly resistant to thermal shock and acids—perfect for specialized experiments.

How to Use an Evaporating Dish Safely

Step-by-Step Instructions

1. Place the evaporating dish on a wire gauze over a tripod.
2. Add the liquid to be evaporated.
3. Use a Bunsen burner for gentle heating.
4. Wait till most liquid has evaporated, then cool before removing.

Safety Precautions

• Always wear gloves and goggles.
• Heat slowly to avoid splashing.
• Use tongs when handling hot dishes.

Common Mistakes to Avoid

• Heating too fast.
• Using on a direct flame without a gauze.
• Letting it boil dry.

Cleaning and Maintenance

Cleaning Techniques

• Rinse with water while still warm (but not hot).
• For stubborn residues, use a dilute acid or detergent solution.

Do’s and Don’ts of Handling

• Do: Use gently, clean after every use.
• Don’t: Drop it in cold water immediately after heating—thermal shock can crack it.

Benefits of Using Evaporating Dishes

High Heat Resistance

They can take a lot of heat, literally. Perfect for Bunsen burner use.

Reusability

Durable and easy to clean, making them cost-effective.

Accurate Results

The design ensures minimal spillage and easy observation.

Alternatives to Evaporating Dishes

Watch Glass

Used for small-scale evaporation but less heat-resistant.

Crucibles

Can withstand very high temperatures but are deeper and not ideal for observation.

Beakers

Good for boiling but not for evaporation, due to their depth and shape.

Evaporating Dish vs. Crucible

Key Differences

• Evaporating Dish: Shallow, used for gentle heating and evaporation.
• Crucible: Deep, used for very high-temperature reactions.

When to Use Each

• Use evaporating dishes for evaporating solvents or crystallizing solutions.
• Use crucibles for decomposing substances at high temperatures.

Top Brands and Products

Recommended Brands for Labs

• Pyrex
• Corning
• Coorstek
• United Scientific

Pricing and Quality Comparison

Porcelain dishes range from $5 to $20 depending on size and brand. Quartz types are premium and can cost $50+.

Buying Guide

What to Look For Before Buying

• Material
• Size
• Compatibility with heat source
• Chemical resistance

Where to Buy (Online & Offline)

• Online: Amazon, Fisher Scientific, LabX
• Offline: Lab equipment suppliers, school science departments

Troubleshooting Tips

Cracks and Leaks

• Inspect regularly for hairline cracks.
• Replace immediately if damaged—safety first!

Staining Issues

• Soak in a vinegar solution or mild acid overnight.
• Avoid abrasive scrubbers.

Real-World Uses

Industry Applications

• Used in food science for moisture analysis.
• Employed in pharmaceutical industries for testing solubility.

Research and Development Use

• Common in R&D labs for controlled chemical reactions.
• Crucial for qualitative analysis of salts and minerals.

Innovations and Modern Uses

Digital Integration in Labs

Some modern labs use automated heating plates and data sensors even with traditional evaporating dishes.

New Materials

Advanced ceramics and composite materials are now being used to improve durability and thermal resistance.

Conclusion

An evaporating dish might look like a simple bowl, but its role in scientific discovery is massive. From high school chemistry labs to cutting-edge pharmaceutical research, it continues to be an unsung hero. Choosing the right material and using it properly ensures accurate results, safety, and longevity. So the next time you see that shallow little dish—know it’s doing some heavy lifting behind the scenes!

FAQs

Q1: Can I use an evaporating dish on a direct flame? A: Yes, but always with a wire gauze underneath to distribute the heat evenly.

Q2: What is the maximum temperature an evaporating dish can handle? A: Porcelain dishes can typically withstand up to 1000°C, depending on the quality.

Q3: Is it dishwasher-safe? A: No. Clean it manually to avoid damage and preserve its integrity.

Q4: Why is my evaporating dish cracking after use? A: Likely due to thermal shock. Never expose it to sudden temperature changes.

Q5: Can I use it for food or kitchen purposes? A: Absolutely not. It’s strictly for laboratory use and not food-safe.