The key difference between crucible and evaporating dish is that crucible is a container used for the melting of metals or subjecting of substances to high temperatures whereas evaporating dish is a container used for evaporation of solutions and supernatant liquids.
Crucible and evaporating dish are important laboratory glassware that often comes into contact with high temperatures. These containers appear closely similar in shape but are different from each other according to their composition and application.
CONTENTS
1. Overview and Key Difference
2. What is a Crucible
3. What is an Evaporating Dish
4. Side by Side Comparison – Crucible vs Evaporating Dish in Tabular Form
5. Summary
What is a Crucible?
Crucible is a container made of either ceramic or metal, and it is useful for melting or heating substances to very high temperatures. Historically, these containers were made from clay instead of ceramic, and they can be made from any material that is relatively inert and can withstand high temperatures.
Figure 01: A Modern Crucible
Moreover, we can use this glassware in the laboratory to contain chemical compounds that are heated to extremely high temperatures. There are several sizes of crucibles available commercially, and typically these containers come with a lid that is fit for the size of the crucible. We can heat a crucible over the flame. Often, this container must be kept on a pipeclay triangle where the flame can be adjusted to the centre of this triangle.
Generally, manufacturers use high-temperature-resistant materials such as porcelain, alumina and inert metals to make crucibles. Earlier, people used platinum for this production so that it can withstand high temperatures. Nowadays, we use ceramics such as alumina, zirconia, and magnesia since platinum is very expensive.
Furthermore, the lid is typically made lose-fitting to the crucible, which helps in allowing the gases to escape the sample in the crucible. There are various sizes and shapes of crucibles available commercially.
What is an Evaporating Dish?
An evaporating dish is a laboratory container that is useful in the evaporation of solutions and supernatant liquids. Sometimes, the sample in this dish is heated to its melting point. These containers are useful for the evaporation of excess solvents (such as water) to get a concentrated solution or sometimes a solid precipitate from a solution.
Figure 02: Different Sizes of Evaporating Dishes
Mostly, evaporating dishes are made from porcelain or borosilicate glass that can withstand high temperatures. There are shallow glass evaporating dishes that are usually known as watch glasses. These glasses cannot be used for very high-temperature applications.
Generally, the capacity of an evaporating dish is in the range of 3 – 10 mL. However, there can be some large dishes, e.g. 100mL, depending on the application. These large dishes are in a different shape and are more hemispherical. Most often, an evaporator is useful for quantitative analysis.
What is the Difference Between Crucible and Evaporating Dish?
Crucible and evaporating dish appear in closely similar shapes but are different from each other according to the composition and application. The key difference between crucible and evaporating dish is that crucible is a container used for the melting of metals or subjecting substances to high temperatures, whereas evaporating dish is a container used for the evaporation of solutions and supernatant liquids.
Below is a list of differences between crucible and evaporating dish in tabular form.
Summary – Crucible vs Evaporating Dish
Crucible and evaporating dish are important laboratory glassware that often comes into contact with high temperatures. A crucible is a container used for the melting of metals or subjecting substances to high temperatures, while an evaporating dish is a container used for the evaporation of solutions and supernatant liquids. Thus, this is the key difference between crucible and evaporating dish.
Reference:
1. “Crucible.” Wikipedia, Wikimedia Foundation, 21 Feb. 2021, Available here.
Image Courtesy:
1. “Czochralski method used crucible 1” By Twisp assumed (based on copyright claims). – No machine-readable source provided. Own work assumed (based on copyright claims) (Public Domain) via Commons Wikimedia
2. “Abdampfschalen verschiedene Groessen” By Simon A. Eugster – Own work (CC BY-SA 3.0) via Commons Wikimedia