## Question

### Solution

Correct option is

Silica

Quartz is a covalent crystal having a framework of silicates or silica, ie, a three dimensional network when all the four oxygen atoms of each of SiO4tetrahedron are shared.

#### SIMILAR QUESTIONS

Q1

KCI crystallises in the same type of lattice as does NaCI.

The ratio of the side of the unit cell for NaCI to that for KCI is

Q2

The unit cell of aluminum is a cube with an edge length of 405 pm. The density of aluminum is 2.70 g cm-3. The type of unit cell is

Q3

A binary solid X+ Y- has a zinc blende structure with Y- ions forming the lattice and X+ ion occupying 25% tetrahedral sites. The formula of the solid is

Q4

Gold (at wt. 197g mol-1) crystallises is a cubic closest packed structures (the face – centred cubic) and has a density of 19.3g/cm2. Its atomic radius is

Q5

Calcium metal crystallizes in fcc lattice with edge length 556 pm. Calculate the density (in g cm-3) of metal if it contains 0.2% Schottky defects.

Q6

Which of the following statements about amorphous solids is incorrect?

Q7

An alloy of Cu, Ag and Au is found to have Cu forming the simple cubic closed packed lattice. If the Ag atoms occupy the face centres and Au is present at the body centre, the formula of the alloy will be

Q8

If the radius ratio is in the range of 0.414 – 0.732, then the coordination number will be

Q9

X – ray analysis shows that the unit cell length in NaCl is 562.8 pm. Calculate the density you would expect on this basis,

NA = 6.023 × 1023 mol-1.

Q10

If the distance between Na+ and Cl- ions in NaCl crystal is ‘a’ pm what is the length of the cell edge?