Learn Unit I: Chemical Substances - Nature and Behaviour with Top Tutors

To observe what happens when quicklime (calcium oxide) is added to water in a beaker, follow these steps:

1. Take a small amount of quicklime (calcium oxide) and place it in a clean, dry beaker.
2. Add a small amount of water to the quicklime in the beaker, using a dropper or a stirring rod to mix them together.
3. Observe the reaction carefully and note down any changes that occur.

4. Two important observations of the reaction are:
   • The mixture produces heat and generates steam, indicating an exothermic reaction.
   • The quicklime dissolves in water to form calcium hydroxide (slaked lime), accompanied by the release of heat and the formation of a milky white suspension.

The type of reaction taking place is a chemical reaction, specifically an exothermic reaction, in which quicklime (calcium oxide) reacts with water to form calcium hydroxide (slaked lime) and release heat.

Double bond or double covalent bond: A double bond, also known as a double covalent bond, is a type of chemical bond formed when two atoms share two pairs of electrons. This sharing of electrons results in the formation of a strong bond between the atoms. Examples of molecules containing double bonds include ethene (C2H4) and oxygen (O2).

Triple bond or triple covalent bond: A triple bond, also known as a triple covalent bond, is a type of chemical bond formed when two atoms share three pairs of electrons. This sharing of electrons results in the formation of a very strong bond between the atoms. Examples of molecules containing triple bonds include nitrogen gas (N2) and acetylene (C2H2).

Physical properties of carbon compounds or covalent compounds: Some physical properties of carbon compounds or covalent compounds include:

• Low melting and boiling points
• Often exist as gases, liquids, or solids at room temperature
• Non-conductive of electricity in the solid state
• Often have low solubility in water
• May exhibit a wide range of colors, odors, and textures