Among the following the least thermally stable is
K2CO3
Na2CO3
BaCO3
Li2CO3
D.
Li2CO3
Thermal stability of carbonates increases on moving down a group. Thus, lithium carbonate, Li2CO3 is least thermally stable.
Li2CO3 Li2O +CO2
Name the type of the structure of silicate in which one oxygen atom of [SiO4]4- is shared?
Sheet silicate
Pyrosilicate
Three dimensional silicate
Linear chain silicate
The catenation tendency of C, Si and Ge is in the order Ge < Si < C. The bond energies (in kJ mol-1) of C-C, Si-Si and Ge-Ge bonds, respectively are
348, 167, 180
348, 180, 167
167, 180, 348
180, 167, 348
Number of oxygen atoms shared per Si tetrahedron in
I. two dimensional sheet structured silicates
II. cyclic silicates and
III. single strand chain silicates respectively are
3, 3, 2
3, 2, 2
4, 3, 1
4, 3, 2
Pure silicon doped with phosphorus is a
metallic conductor
insulator
n-type semiconductor
p-type semiconductor