Question

The silicate anion in the mineral kinoite is a chain of three $Si{O}_4$ tetrahedra that share corners with adjacent tetrahedra. The mineral also contains $C{a}^{2+}$ ions, $C{u}^{2+}$ ions and water molecules in a 1:1:1 ratio. The mineral is represented as :

• A. $CaCuS{i}_3{O}_{10}{H}_{2}O$
• B. $C{a}_{2}C{u}_{2}S{i}_3{O}_{10}{H}_{2}O$
• C. $C{a}_{2}C{u}_{2}S{i}_3{O}_{10}2H_{2}O$
• D. none of these

Answer 1

Answer: (C)

$C{a}_{2}C{u}_{2}S{i}_3{O}_{10}2H_{2}O$

The mineral is represented as $C{a}_{2}C{u}_{2}S{i}_3{O}_{10}2H_{2}O$.
The charge on $S{i}_3{O}_{10}$ unit is $-8$. It is balanced by two calcium ions each with $+2$ charge and two copper ions, each with $+2$ charge.
Also, the ratio of $C{a}^{2+}$ ions, $C{u}^{2+}$ ions and water molecules is $1:1:1$ ratio.