Question

Calculate the number of atoms present in 40g of Sulphur. Given atomic mass of S=32 ​

Answer 1

Answer :

Molar mass of sulphur = 32 g/mol

Given mass of sulphur = 40 g

Number of moles = Given mass / Molar Mass

So, number of moles of sulphur = 40/32 = 1.25 moles

We know that,

In 1 mole of atom there are 6.022 × 10^23 number of atoms.

So, In 1.25 moles of Sulphur arom, number of atoms = 1.25 × 6.022 × 10^23 = 7.5275 × 10^ 23 atoms

Answer 2

The number of atoms present in 40g of Sulphur is 7.527 × 10²³ atoms.

Number of moles=given mass ÷ Molar mass

One mole of any substance is equal to 6.022 ×10²³ which is called Avogadro's constant.

Explanation:

Given the atomic mass of sulphur=32g/l

number of atoms of sulphur =40gm

Moles =Mass ÷Molar mass

Moles =40/32

Moles= 1.25 moles

We know that

1 mole of an atom consists of 6.022 ×10²³ number of atoms

then 1.25 moles of a sulphur atom consist of 1.25 × 6.022 ×10²³

=7.527 × 10²³ atoms

Number of atoms present in 40g of Sulphur is 7.527 × 10²³ atoms.