Question

Among the following statements, the incorrect one is:
A.Calamine and siderite are carbonates
B.Argentite and cuprite are oxides
C.Zinc blende and pyrites are sulphides
D.Malachite and azurite are ores of copper

Answer 1

The chemical formula of calamine and siderite are $ZnC{O_3}{\text{ and }}FeC{O_3}$.
The chemical formula of argentite and cuprite are $A{g_2}S{\text{ and }}C{u_2}O$.
The chemical formula of zinc blende and pyrites are $ZnS{\text{ and }}Fe{S_2}$.
The chemical formula of malachite and azurite are$CuC{O_3}.Cu{(OH)_2}{\text{ and }}C{u_3}{(C{O_3})_2}{(OH)_2}$.

Complete answer:
Calamine and siderites have carbonates as $C{O_3}$.
Argentite has the chemical formula of $A{g_2}S$, whereas cuprite has the chemical formula of $C{u_2}O$ and hence argentite belongs to sulphides and cuprite is oxide.
Zinc blende and pyrite both belong to the sulphide group since their chemical formulae are $ZnS{\text{ and }}Fe{S_2}$ respectively.
Malachite has the chemical formula of $CuC{O_3}.Cu{(OH)_2}$and azurite has the chemical formula of $C{u_3}{(C{O_3})_2}{(OH)_2}$ and both of them are ores of copper.
Therefore, option (B) is incorrect.

Note:
Argentite is a silver sulfide mineral and is an important ore of silver deposits. It contains $87\%$ of silver and forms blackish-grey coatings.
Cuprite is formed from the oxidized zone of Copper iodide. Cuprite takes the shape of crystals or grains or earthy masses and can appear to be transparent to translucent and colored in red to almost black.