|
|
Calcium Oxide (Quick-lime) - 25g
|
|
|
Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline crystalline solid at room temperature.
The broadly used term lime connotes calcium-containing inorganic materials, in which carbonates, oxides and hydroxides of calcium, silicon, magnesium, aluminum, & iron predominate, such as limestone. By contrast, quicklime specifically applies to a single chemical compound.
Calcium oxide is usually made by the thermal decomposition of materials such as limestone, that contain calcium carbonate (CaCO3; mineral calcite) in a lime kiln. This is accomplished by heating the material to above 825 °C, a process called calcination or lime-burning, to liberate a molecule of carbon dioxide (CO2); leaving quicklime. The quicklime is not stable and, when cooled, will spontaneously react with CO2 from the air until, after enough time, it is completely converted back to calcium carbonate.
Quicklime is relatively inexpensive. Both it and a chemical derivative (calcium hydroxide) are important commodity chemicals.
Quicklime produces heat energy by the formation of the hydrate, calcium hydroxide, by the following equation:
CaO (s) + H2O (l) Ca(OH)2 (aq) (ΔHr = −63.7 kJ/mol of CaO)
The product, commonly called "slaked lime", has many uses on its own. As it hydrates, an exothermic reaction results. The hydrate can be reconverted to quicklime by removing the water by heating it to redness to reverse the hydration reaction. One liter of water combines with approximately 3.1 kg of quicklime to give calcium hydroxide plus 3.54 MJ of energy. This process can be used to provide a convenient portable source of heat, as for on-the-spot food warming in a self-heating can.
When quicklime is heated to 2400 °C (4300 °F), it emits an intense glow. This form of illumination is known as a limelight, and was used broadly in theatrical productions prior to the invention of electric lighting.
Precipitated calcium carbonate, made by dropping calcium oxide into water, is used by itself or with additives as a white paint, known as whitewashing.
Annual worldwide production of quicklime is around 283 million metric tons. China is by far the world's largest producer, with a total of around 170 million metric tons per year. The United States is the next largest with around 20 million metric tons per year.
NOTE:
The information contained herein is believed to be accurate and is offered in good faith for the user's consideration and investigation. No warranty is expressed or implied regarding the completeness or accuracy of this information, whether originating from chem Kit Depot LLC. or from an alternate source. Users of this material should satisfy themselves by independent investigation of current scientific and medical information that this material may be safely handled.
Be aware, that the chemical(s) contained in this site are prepackaged in small quantities and are intended for educational use in experiments by students and/or educators/home schoolers.
By purchasing this item, you agree to:
- NOT hold Chem Kit Depot LLC liable in any form.
- Accept all responsibility for the purchased item once it has left our facility.
- Use this product for the purposes intended by the seller.
- Obey ALL LOCAL, COUNTY, STATE and FEDERAL LAWS governing the use of this product.
- Read the Material Data Safety sent with the product and follow the recommendations.
- Will dispose of chemicals in the proper manner.
- Are 21 years or older.
We reserve the right to limit the quantities on any chemical!!
|
|
|
|