Calculate the number of each atom in 2.5 gram of caco3

of would contain:

Explanation:

Look up the Avogadro constant: .

For example, " of carbon atoms" would contain carbon atoms (approximately ) by definition.

Look up the relative atomic mass of carbon, calcium, and oxygen on a modern periodic table:

In other words, the mass of of calcium atoms would be . The mass of of carbon atoms would be , and the mass of of oxygen atoms would be .

As the formula suggests, every formula unit of this ionic compound includes one calcium atom, one carbon atom, and three oxygen atoms. The formula mass of would give the mass of every mole of formula units.

Calculate the formula mass of from the relative atomic mass data:

.

Calculate the number of formula units in that of this compound:

.

In other words, of would contain approximately formula units.

Again, there are one calcium atom, one carbon atom, and one oxygen atom in every formula unit. That approximately formula units would thus contain:

Make use of the Avogadro constant to convert the numbers.

For example, the number of calcium atoms in that approximately of calcium atoms would be:

.

Likewise, the number of carbon atoms in that approximately of carbon atoms would be:

.

The number of oxygen atoms in that approximately of oxygen atoms would be:

.