Question

Number of atoms present in 0.2 mol of Na2S4o6 is NA
Avogadros number)
1.2 NA
2.0 NA
2.4 NA
0.2NA​

Answer 1

Given:

0.2 mol of Na₂S₄O₆

To Find:

Number of  atoms in the given compound

Solution:

The number of atoms in one mole of any compound is equal to the Avogadro's number (NA)

Number of atoms in 1 mole of Na₂S₄O₆ = Atomicity x NA

Total number of atoms in one mole of Na₂S₄O₆  = 12

Number of S atoms in 0.2 mole of Na₂S₄O₆ = (0.2 x12 x NA) = 2.4 NA

So, the number of atoms present in 0.2 mol of  Na₂S₄O₆ is 2.4 NA

Answer 2

Given:

0.2 moles of $Na_{2}S_{4}O_{6}$ has been provided.

To find:

Number of atoms ?

Calculation:

In this type of questions, it's best to apply Unitary Method:

$\implies$ 1 mole of $Na_{2}S_{4}O_{6}$ has

$= (2 + 4 + 6) N_{A}= 12N_{A} \: atoms$

$\implies$ 0.2 mole of $Na_{2}S_{4}O_{6}$ has

$= 12N_{A} \times 0.2$

$= (12 \times 0.2)N_{A} = 2.4N_{A} \: atoms$

So, number of atoms present is 2.4 N_(A) atoms.