The double-stranded silicate ion shown in the picture below combines with calcium and magnesium to form the mineral tremolite,which is a form of asbestos.What is the formula and charge of the repeating unit of the silicate ion?

Question

Quizplus · Accepted Answer

The repeating unit of the silicate ion is determined by counting the number of tetrahedrons (SiO4) and the number of shared oxygens (O). In this case, there are 4 tetrahedrons and 11 shared oxygens, which gives us the formula Si4O11. This has a charge of 12- (4 x 4- tetrahedron charge + 11 x 2- oxygen charge). When combined with calcium and magnesium, it forms the mineral tremolite, which is a form of asbestos. Of the choices given, the only one with Si4O11 as the repeating unit is B.

The Double-Stranded Silicate Ion Shown in the Picture Below Combines