Question

what is the atomic weight of an element X for which a sample containing 1.58×10 raise to power22 atoms weigh 1.05 g

Answer 1

Given Conditions,
No. of atoms in a sample = 1.58 × 10²² atoms.
Mass of the sample = 1.05 g.

Let the atomic mass of the element X be 'a' g/mole

Using the formula,
No. of moles = Mass/Molar mass.
∴ No. of moles = 1.05/a

Now,
No. of atoms = No. of mole × Avogadro's number.
∴ 1.58 × 10²² = 1.05/a × 6.022 × 10²³
∴ a = 40.02 g

Thus, the atomic weight of the Elemnt X is 40.02 g.


I hope it will helps you.

Answer 2

Answer:

Explanation:Given Conditions,

No. of atoms in a sample = 1.58 × 10²² atoms.

Mass of the sample = 1.05 g.

Let the atomic mass of the element X be 'a' g/mole

Using the formula,

No. of moles = Mass/Molar mass.

∴ No. of moles = 1.05/a

Now,

No. of atoms = No. of mole × Avogadro's number.

∴ 1.58 × 10²² = 1.05/a × 6.022 × 10²³

∴ a = 40.02 g