Question

How many unit cell present in 58.8gm of nacl?

Answer 1

Calculate the moles of NaCl as follows: 

molar mass of NaCl  = 58.5

mass = 58. g

moles = mass/molar mass

           = 58.5 / 58.5 

     1 mole

According to Avagadro's constant, 1 mole of any substance has exactly 6.022 × 10²³ molecules/atoms/unit cells.

 

Therefore in 58.5 g of NaCl there will be approximately 6.022 × 10²³ unit cells.

Answer 2

Atomic mass of sodium = 23 g

This means, 23 g of sodium contains 6.023 x 1023 atoms

Now, number of atoms in a unit cell of bcc structure = 2

Therefore,

the number of unit cells which contain= /2 atoms

= 6 x 1022 unit cells.