Question

Calculate the number of atom in each of the following:(Atomic Mass of I=127 u) 254 g of Iodine(I)

Answer 1

Answer:

( a ) 2 atoms

( b ) 12.046 * 10^{24} atoms

Explanation :-

Given :-

Atomic mass of I = 127 u

To Find :-

No. of atoms in 254 u of Iodine

No. of atoms in 254 g of Iodine

Solution :-

( a )

No. of atoms = given mass / atomic mass

No. of atoms = 254/127 = 2 atoms.

------------------------

( b )

we know that,

Mass no. = atomic no.

Atomic no. of I = 127 u

-------------------------

Therefore, Molar mass = 127 g

No. of moles = 254/127 = 2

Now,

No. of atoms = no. of moles × Avogadro's no.

No. of atoms = 2 *6.022*10^{24}

No. of atoms = 12.046*10^{23}