You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard XII

Chemistry

Density

The density o...

Question

The density of $C a O$ is $3.35$ gm $/ c m^{3}$ . The oxide crystallizes in one of the cubic systems with an edge of $4.80 o A$ . How many $C a^{2 +}$ ions belong to each unit cell? $[C a O = 56]$

3

No worries! We‘ve got your back. Try BYJU‘S free classes today!

4

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

6

No worries! We‘ve got your back. Try BYJU‘S free classes today!

2

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B $4$
Given,
$a = 4.8 ˚ A$
$M_{A} = 56$
$ρ = 3.35$ $g / c m^{3}$
$N_{A} = 6.023 \times 10^{23}$
$ρ = \frac{Z \times M_{A}}{N_{A} \times a^{3}}$
$Z = \frac{ρ \times N_{A} \times a^{3}}{M_{A}}$
$Z = \frac{3.55 \times 6.023 \times 10^{23} \times {4.8}^{3} \times 10^{- 24}}{56}$
$Z = 4$
Therefore, $4 C a^{2 +}$ ions belong to each unit cell.

Suggest Corrections

Similar questions

The density of CaO is 3.35 gm/cm³. The oxide crystallises in one of the cubic systems with an edge of 4.80 Å. How many Ca⁺⁺ ions and O^-2 ions belong to each unit cell, and which type of cubic system is present?

Q. Pyrite (

F e S_{2}

), crystallizes in a cubic unit cell with a cell edge of

0.540 nm

. The density of pyrite is

5.02 {g/cm}^{3}

. How many

F e^{2 +}

and

S_{2}^{2 -}

ions are present in a single unit cell? (

S = 32 u, F e = 56 u

)

Q. The density of potassium bromide crystal is

2.75

/ c m^{3}

and the length of an edge of the unit cell is

654

pm. The unit cell of

K B r

is one of the three types of cubic unit cell. How many of formula units of

K B r

are there in a unit cell?

[K B r = 119]

Q. Ferrous oxide has a cubic structure and the edge length of its unit cell is

5.0 A^{\circ}

. Assuming the density of ferrous oxide to be

3.84 {g/cm}^{3}

, the number of

F e^{2 +}

and

O^{2 -}

ions present in each unit cell should be:

(use N_{A} = 6 \times 10^{23})

Q. Pyrite (

F e S_{2}

), crystallizes in a cubic unit cell with a cell edge of

0.540 nm

. The density of pyrite is

5.02 {g/cm}^{3}

. How many

F e^{2 +}

and

S_{2}^{2 -}

ions are present in a single unit cell? (

S = 32 u, F e = 56 u

)

Join BYJU'S Learning Program

The density of CaO is 3.35 gm/cm3. The oxide crystallizes in one of the cubic systems with an edge of 4.80oA. How many Ca2+ ions belong to each unit cell? [CaO=56]

The correct option is B 4Given,a=4.8˚AMA=56ρ=3.35 g/cm3NA=6.023×1023ρ=Z×MANA×a3Z=ρ×NA×a3MAZ=3.55×6.023×1023×4.83×10−2456Z=4Therefore, 4Ca2+ ions belong to each unit cell.

The density of $C a O$ is $3.35$ gm $/ c m^{3}$ . The oxide crystallizes in one of the cubic systems with an edge of $4.80 o A$ . How many $C a^{2 +}$ ions belong to each unit cell? $[C a O = 56]$