Question

Calculate the number of atom in each of the following ( given atomic mass of I-127) a-254u of iodine and b-254g of iodine

Answer 1

Answer:

a) 2 atoms

b) 12.046*10^24 atoms

Explanation :

We know from the question that the atomic mass of Iodine is given as 127u.

( a ) We know the formulae to find the number of atoms which is given mass / atomic mass of that element.

So, the number of atoms will be 254/127 = 2 atoms.

( b )

Since,we know the Molar mass which is 127 g.

Hence, the number of moles will be 254/127 = 2.

Therefore, the number of atoms will be no. of moles × Avogadro's no.

So, the number of atoms = 2*6.022*10^23

Number of atoms will be 12.046*10^23.

Answer 2

Answer:

a) 254 u of I contains 2 atoms, b) 254 g of I contains 1.2044*10^24 atoms.

Explanation:

Given:Mass of Iodine=127 u.

(a) we know that no. of atoms =Mass given/atomic mass of that element.

=>no. of atoms = 254 u/127 u=2 atoms

(b) we know molar mass of I =127 g.

=>no. of moles =254 g/127 g=2 moles.

Also we know that, no. of atoms= no of moles * Avogadro's no.

=>no. of atoms = 2*6.022 *10^23=12.044 *10^ 23

=1.2044 *10^24 atoms.