Question

calculate the number of atom in each of the following (given atomic mass of I=127 u
a. 254 u iodine (I)
b. 254 g iodine (I)​

Answer 1

Answer:

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.

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( b )

we know that,

Mass no. = atomic no.

Atomic no. of I = 127 u

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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* 6.023$10^{24}$

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

Answer 2

Answer:

2 mol and 1.2044×10^24atoms

Explanation:

a)..molar mass of iodine =127g/mol

number of mols =Mass of substance / molar mass of substance

=254g/127g/mol=2mol

b).. number of atoms= Number of moles×avagadro's number

=2mol×6.022×10^23 atom

=12.044×10^24atoms

=1.2044×10^23 atoms