Question

Correct the following statement:

For example: ‘Chlorine is a bleaching agent.’

Should read: 'Moist chlorine is a bleaching agent.

Lead bromide conducts electricity.

Answer 1

Ionic Theory:

• In solutions, electrolytes are present in the form of ions and permit current flow through them.
• The movement of ions is responsible for the flow of current.
• Lead bromide $\left({\mathrm{PbBr}}_2\right)$ is an electrolyte that will conduct electricity either in an aqueous solution or in a molten state.

Solid form of Lead bromide $\left({\mathrm{PbBr}}_2\right)$

• Lead bromide is an ionic compound that contains Lead $\left({\mathrm{Pb}}^{2+}\right)$ and Bromide $\left({\mathrm{Br}}^{-}\right)$ ions.
• In solid state, the ions are not allowed to move freely as they are bound via strong electrostatic attraction forces.
• Due to this, solid Lead bromide does not conduct electricity.

Molten and aqueous forms of Lead bromide $\left({\mathrm{PbBr}}_2\right)$

• In molten form, these ions are free to move. Therefore, molten lead bromide conducts electricity.
• In the aqueous state, the ions become free as they get solvated in water and therefore, conduct electricity.
• The chemical reaction is as follows

${\mathrm{PbBr}}_2\left(\mathrm{s}\right)+\mathrm{Water}\left(\mathrm{l}\right)\to {\mathrm{Pb}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{Br}}^{-}\left(\mathrm{aq}\right)$

Hence, the correct statement is “Lead bromide conducts electricity in a molten or aqueous state.”