Question

Which of the following contains maximum number of atoms ?

(a) 2.0 moles of S8

(b) 6.0 moles of S

(c) 2.0 moles of SO2

(d) 44.8 L of SO2 at STP​

Answer 1

Given:

a) 2.0 moles of S8

(b) 6.0 moles of S

(c) 2.0 moles of SO2

(d) 44.8 L of SO2 at STP​

To Find: Number of atoms = N

Solution:

Formula used:

Number of atoms(N) = number of moles(n) × Nₐ × atomicity

                                  Nₐ = Avagadro number = 6.023 × 10²³

a)2moles of S₈( atomicity = 8)

N = 2 × 6.023 × 10²³ × 8

N = 96.37 × 10²³ atoms

b)6.0 moles of S (atomicity = 1)

N = 6 × 6.023 × 10²³

N = 36.138 × 10²³ atoms of S

c) 2.0 moles of SO2( atomicity = 1 S + 2 O = 3)

N = 2 × 6.023 × 10²³ × 3

N = 36.138 × 10²³ atoms

d) 44.8 L of SO2 at STP​(atomicity = 3)

number of moles - n = Given volume/ 22.4L

n = 44.8/22.4

n = 2

N = n × Nₐ × atomicity

N = 2 × 6.023 × 10²³ × 3 (same as c)

N = 36.138 × 10²³ atoms of SO₂

Hence all have the same and least number of atoms except, 2 moles of S₈ has the highest number of atoms. (option a)