The number of oxygen atoms (O) in 0.24g of calcium carbonate CaCO3

0.036  × 10²³ oxygen atoms

Explanation:

Given data:

Mass of compound = 0.24 g

Number of oxygen atoms = ?

Solution:

First of all we will calculate the number of moles of compound.

number of moles = mass/ molar mass

Number of moles = 0.24 g/ 100.1 g/mol

Number of moles = 0.002 mol

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole of CaCO₃ contain 3 moles of oxygen atom.

0.002 mol × 3 = 0.006 moles of oxygen atoms.

Number of oxygen atoms:

1 mole = 6.022 × 10²³ number of oxygen atoms

0.006 mol ×  6.022 × 10²³ f oxygen atoms / 1 mol

0.036  × 10²³ oxygen atoms

the answer would be a