Question

${\text{CuC}}{{\text{O}}_{\text{3}}}{\text{.Cu(OH}}{{\text{)}}_{\text{2}}}$ is known as Malachite (green). State true or false.
A.True
B.False
C.Cannot be determined
D.None of the above

Answer 1

Malachite green is a green coloured compound found in nature. ${\text{CuC}}{{\text{O}}_{\text{3}}}{\text{.Cu(OH}}{{\text{)}}_{\text{2}}}$ is found in mineral state as green colour in nature.

Complete step by step answer:
${\text{CuC}}{{\text{O}}_{\text{3}}}{\text{.Cu(OH}}{{\text{)}}_{\text{2}}}$ is known as basic copper carbonate. The chemical name of this compound is copper carbonate hydroxide. It is an ionic salt having ${\text{C}}{{\text{u}}^{2 + }}$ ions, ${\text{C}}{{\text{O}}_3}^{2 - }$ ions and ${\text{O}}{{\text{H}}^{\text{ - }}}$ ions. They are named as cupric ion, carbonate ion and hydroxide ion, respectively. The molecular mass of this compound is ${\text{221}}{\text{.114 g mo}}{{\text{l}}^{ - 1}}$, which can be calculated by adding the molecular mass of each atom present in the compound. It is insoluble in water with a density of 4 ${\text{mo}}{{\text{l}}^{{\text{ - 1}}}}$.
The common way of writing this compound is ${\text{C}}{{\text{u}}_2}{\text{C}}{{\text{O}}_{\text{3}}}{{\text{(OH)}}_2}$. It occurs in nature in the form of a mineral called malachite. Its actual colour is green and is crystalline in nature. Azurite is an another blue crystalline solid with the formula ${\text{C}}{{\text{u}}_3}{{\text{(C}}{{\text{O}}_{\text{3}}}{\text{)}}_2}{{\text{(OH)}}_2}$.
It is prepared by reacting copper sulphate with sodium carbonate. It can also be prepared with sodium bicarbonate. Both the reactions are given below:
${\text{2CuS}}{{\text{O}}_{\text{4}}}{\text{ + 2N}}{{\text{a}}_2}{\text{C}}{{\text{O}}_{\text{3}}}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{O}} \to {\text{CuC}}{{\text{O}}_{\text{3}}}{\text{.Cu(OH}}{{\text{)}}_{\text{2}}}{\text{ + 2N}}{{\text{a}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{ + C}}{{\text{O}}_{\text{2}}}$
${\text{2CuS}}{{\text{O}}_{\text{4}}}{\text{ + 4NaHC}}{{\text{O}}_{\text{3}}} \to {\text{CuC}}{{\text{O}}_{\text{3}}}{\text{.Cu(OH}}{{\text{)}}_{\text{2}}}{\text{ + 2N}}{{\text{a}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{ + 3C}}{{\text{O}}_{\text{2}}}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{O}}$
They are very much pigmented materials and also used in makeup products such as lipsticks. It is also used as algaecide by farmers and in aquaculture though it is toxic to human being.
The given sentence is true.

Hence, the correct option is A that is true.

Note:
Often this compound is named wrong as cupric carbonate or copper carbonate and many other names. The pure copper carbonate is ${\text{CuC}}{{\text{O}}_{\text{3}}}$ which does not occur naturally because of aerial oxidation in the presence of air and moisture.