STRUCTURE OF QUICK LIME
WITH DIAGRAM
Answers
Explanation:
Calcium oxide, also known as quicklime, is an alkaline substance that has been in use since the medieval age. It is believed that quicklime is one of the oldest chemicals known to the human race. It can also be referred to as burnt lime or lime.
Calcium Oxide Powder
Calcium oxide has a medium viscosity and a high surface tension, plus a high to intermediate expansion and contraction rate. This material isn’t volatile at ceramic temperatures. Calcium oxide has a moderate effect on colour, except in large amounts when it may have a bleaching effect on iron oxide. It also exists in the colour of kaki/tomato reds.
Preparation of Calcium Oxide
Calcium oxide can be produced by thermal decomposition of materials like limestone or seashells that contain calcium carbonate (CaCO3; mineral calcite) in a lime kiln.
The process that is used to prepare burnt lime is known as calcination. It is a process that starts with thermally decomposing the reactants at high temperatures but ensuring that the temperature is kept well below the melting point.
Calcium carbonate undergoes calcination at temperatures ranging between 1070oC-1270oC. These reactions are usually held in a rotary kiln. The products formed as a result of the reaction are burnt lime and carbon dioxide.
The carbon dioxide that is formed is immediately removed so that the reaction is preceded until the completion of the process in accordance with Le-Chatelier’s principle.
CaCO3 → CaO + CO2
This reaction is reversible and exothermic in nature in the forward direction.
Structure of CaO Molecules
Calcium oxide molecules contain one calcium cation (which holds a charge of +2) and one oxygen anion (which holds a charge of -2). The structure of calcium oxide is illustrated below.
Calcium Oxide Structure
Thus, it can be understood that calcium oxide is an ionic compound featuring an ionic bond between calcium and oxygen.
Lime Water Formula
The formula for lime water is Ca(OH)2 and the chemical name for lime water is calcium hydroxide. When water is added to lime calcium hydroxide Ca(OH)2 is formed according to the following reaction.
CaO + H2O → Ca(OH)2
This reaction is strongly exothermic and takes place vigorously with the formation of clouds of steam
