Question

Number of atoms present in 3 moles of iron is--------
a) 6.023 x 1023
b) 18.069 x 1023
c) 12.046 x 1023
d) None​

Answer 1

Given:

3 moles of iron

To find:

Number of atoms present in 3 moles of iron = ?

Concept to be used:

The number of atoms present in 1 mole of any element will be equal to Avogadro's number.

Mathematically,

Atoms present in 1 mole of element = $6.022$ × $10^{23}$

Solution:

By applying the concept, it may be written that,

1 mole of iron =  $6.022$ × $10^{23}$ atoms

3 mole of iron = $x$

On cross multiplication,

$x$ × 1 =  $6.022$ × $10^{23}$ × 3

$1x=18.066$ ×  $10^{23}$

Therefore,

$x =$ $18.066$ ×  $10^{23}$

Final answer:

Number of atoms present in 3 moles of iron is  $18.066$ ×  $10^{23}$ . Thus, option (b) is the correct answer