## Question

### Solution

Correct option is

4

Let the number of nickel ions = 98

∴ the number of oxide ions = 100

Total negative charge on O2- ions = 2 × 100 = 200

Let number of  Ni3+ ions = x

∴ Number of Ni2+ ions = 98 – x

x × 3 + (98 - x) × 2 = 200

x = 4

% of Ni as Ni3+ =  × 100 = 4.08%

#### SIMILAR QUESTIONS

Q1

The crystal system of a compound with unit cell dimensions,

a = 0.387, b = 0.387 and c = 0.504 nm, and α = β = 900 and γ = 1200 is

Q2

If Z is the number of atoms in the unit cell that represents the closest packing sequence …… ABC ABC …… the number of tetrahedral voids in the unit cell is equal to

Q3

In which of the following crystals alternate tetrahedral voids are occupied?

Q4

A solid is made of two elements X and Z. the atoms Z are in ccp arrangement while the atom X occupy all the tetrahedral sites. What is the formula of the compound?

Q5

An element occurring in the bcc structure has 12.08 × 1023 unit cells. The total number of atoms of the elements in these cells will be

Q6

The number of sphere contained (i) in one body centred cubic unit cell and (ii) in one face centred cubic unit cell, is

Q7

CsBr crystal has bcc structure. It has an edge length of 4.3. the shortest interionic distance between Cs+ and Br –  ions is

Q8

The number of atoms in 100 g of an fcc crystal with density,

d = 10g/ cm3 and cell edge equal to 100 pm, is equal to

Q9

The number of unit cell in 58.5 g of NaCl is nearly

Q10

In orthorhombic, the value of a, b and c are respectively 4.2, 8.6 and8.3. given the molecular mass of the solute is 155 g mol-1 and that of density is 3.3 g/cc, the number of formula units per unit cell is