Question

Give the names of the elements present in:

aqueous solution of calcium chloride

Answer 1

The aqueous solution of calcium chloride $[{\mathrm{CaCl}}_2(\mathrm{aq}\left)\right]$ is a mixture of two compounds i.e.; Calcium chloride $\left({\mathrm{CaCl}}_2\right)$ and water $\left({\mathrm{H}}_2\mathrm{O}\right)$.

• When any compound is dissolved in water, the solution is said to be an aqueous solution of that compound.

Mixture: When two or more substances (elements or compounds or an element and compound) are mixed in any proportion.

• The components of a mixture can be separated by physical methods of separation.
• Example: A mixture of Sand and Iron $\left(\mathrm{Fe}\right)$ can be separated by the use of a magnet (physical process) where Iron gets attracted to the magnet leaving behind the sand.

Compound: A compound is a pure substance in which elements combine chemically in a fixed composition to give a compound.

• They can be broken down into elements that make up the compound by using chemical or electrochemical methods.
• Example: Water $\left({\mathrm{H}}_2\mathrm{O}\right)$, Common salt i.e. Sodium chloride $\left(\mathrm{NaCl}\right)$

To find out the elements present in the Aqueous solution of calcium chloride:

Step-1: Write the chemical formula of the compounds involved

• Calcium chloride is a compound with the chemical formula ${\mathrm{CaCl}}_2$
• Water is a compound with the chemical formula ${\mathrm{H}}_2\mathrm{O}$

Step-2: Identify the elements present in the compound from their chemical symbols.

S.No	Symbol of the element	Name of the element
1	$\mathrm{Ca}$ (present in calcium chloride)	Calcium
2	$\mathrm{Cl}$ (present in calcium chloride)	Chlorine
3	$\mathrm{H}$ (present in water)	Hydrogen
4	$\mathrm{O}$ (present in water)	Oxygen

Element: An element is a pure substance that cannot be split into simpler substances.

• Example: Hydrogen $\left({\mathrm{H}}_2\right)$, Copper $\left(\mathrm{Cu}\right)$ etc.