Question

On reaction of sodium hydroxide with Lead(II) ion gives the coloured precipitate. Guess the colour.
A. Dark green
B. Pink
C. Red
D. White

Answer 1

Hint:Sodium hydroxide is a dangerous substance and harmful to human beings. It is known as lye or caustic soda and has a chemical formula of NaOH. It has the ability to absorb moisture from air at room temperature. It is crystalline odourless compound.it is used to slow down the process of decomposition of sodium hypochlorite into sodium chlorate and sodium chloride.

Complete answer:
When lead(II) ion is reacted with sodium hydroxide it gives a white color precipitate. The reaction for the same is given below,
\[\rm{{{Pb^{2+}}+2O{{H}^{-}}\to Pb{{(OH)}_{2}}(s)}}\]
Transition metals are the metals which form coloured compounds with other elements. Many compounds of transition metals are soluble in water thereby forming coloured solutions. If a solution of sodium acid is added to a transition metal, a transition metal hydroxide is formed. These hydroxide are not soluble in water due to which the formation of solid precipitate occurs.

Therefore the correct option is D. White

Additional Information:
Sometimes some suspended particles appear in the solution and they precipitate. If copper(II) sulphate hydroxide is added to sodium hydroxide solution the following reaction will take place,
\[\rm{CuS{{O}_{4}}(aq)+2NaOH(aq)\to Cu{{(OH)}_{2}}(s)+N{{a}_{2}}S{{O}_{4}}(aq)}\]
Copper sulphate solution is a blue colour solution which is mixed with colourless solution of sodium hydroxide which gives a blue precipitate of copper hydroxide and a colourless solution of sodium sulphate as the products.

Note:
Sodium hydroxide is used in laboratories for testing Fe(III) ion, when added it gives reddish brown colour precipitate, and with copper(II) ion it gives blue precipitate.
The sodium hydroxide is used as cleaners in drains. It is also used in the chemical industry, metal processing, hydraulic fracturing. It is also used in preparation of soda lime. It is used as a cleansing agent. It is used in extraction of aluminium by purifying bauxite