Question

Consider the following ores.
Siderite, Iron Pyrites, Haematite, Malachite, Cuprite, Copper glance, Sphalerite, Calamine, Zincite.
Out of the above ores, $x$ is the number of ores in which oxidation number of metal is $1$. The value of $4x$ is:

Answer 1

$\begin{array}{cc}\text{Ores}& \text{Oxidation number}\\ \text{Siderite}FeC{O}_3& 2\\ \text{Iron pyrite}Fe{S}_2& 2\\ \text{Haematite}F{e}_2{O}_3& 3\\ \text{Malachite}CuC{O}_3\cdot Cu\left(O{H}_2\right)& 2\\ \text{Cuprite}C{u}_{2}O& 1\\ \text{Copper glance}C{u}_{2}S& 1\\ \text{Sphalerite}ZnS& 2\\ \text{Calamine}ZnC{O}_3& 2\\ \text{Zincite}ZnO& 2\end{array}$
The value of $4x=4\times 2=8$