Home
Class 12
CHEMISTRY
Iron exhibits bcc structure at roomj tem...

Iron exhibits `bcc` structure at roomj temperature. Above `9000^(@)C`, it transformers to `fcc` structure. The ratio of density of iron at room temperature to that at `900^(@)C` (assuming molar mass and atomic radius of iron remains constant with temperature) is

A

`(3sqrt(3))/(4sqrt(2))`

B

`(4sqrt(3))/(3sqrt(2))`

C

`(sqrt(3))/(sqrt(2))`

D

`(1)/(2)`

Text Solution

Verified by Experts

The correct Answer is:
A
For BCC lattice : `Z=2,a=(4r)/(sqrt(3))`
For BCC lattice , `Z=4,a=2sqrt(2)r`
`therefore (d_(25^(@)C))/(d_(900^(@)C))=(((ZM)/(N_(A)a^(3)))_(B"CC"))/(((ZM)/(N_(A)a^(3)))_(F"CC"))`
`=(2)/(4)((2sqrt(2)r)/((4r)/(sqrt(3))))^(3)`
`=((3sqrt(3))/(4sqrt(2)))`
Promotional Banner

Similar Questions

Explore conceptually related problems

Iron exhibits bcc structure at roomj temperature. Above 9000^(@)C , it transformers to fcc structure. The ratio of density of iron at room temperature to that at 900^(@)C (assuming molar mass and atomic radii of iron remains constant with temperature) is

Iron exhibits bcc structure at room temperatutre .Above 900^(@)C .it transitions to fcc structure .The ratio of density of ions at room temperature to that at 900^(@)C (assuming molar mass and atomic , radii of ion remain s constant with temperature ) is

The temperature at which the root mean squres speed of a gas will be half its value at 0^(@)C is (assume the pressure remains constant)

They Y - form of iron has fcc structure (edge length 386) and beta - form has bcc structure (edge length 290 pm) . The ratio of density in Y - form and beta - form is :

The rms velocity of a gas at T °C is double the value at 27 °C. The temperature T of the gas in °C is ( assume that the pressure remains constant)