Calcium carbonate has the chemical formula caco3. a certain quantity of calcium carbonate has 8.35x1025 atoms. how many moles of calcium carbonate is the sample?

Answer

27.7 moles

Explanation:

Data Given:

Chemical formula of Calcium carbonate = CaCO₃

no. of atoms of CaCO₃ = 8.35 x 10²⁵ atoms

moles of CaCO₃= ?

Solution

First convert number of atoms to number of molecules

As

we have 5 atoms per molecule then how many molecules will be for 8.35 x 10²⁵ atoms

So, apply unity formula

               5 atoms  ≅ 1 molecule of CaCO₃

               8.35 x 10²⁵ atoms  ≅ X molecule of CaCO₃

by doing cross multiplication

      X molecule of CaCO₃ = 8.35 x 10²⁵ atoms x 1 molecule / 5 atoms

      X molecule of CaCO₃ = 1.67 x 10²⁵  molecule

Formula will be used

           no. of moles = no. of molecules / Avogadro's number . . . . (1)

Where

Avogadro's number = 6.022 x 10²³ molecules/mol

So,

Put values in equation 1

          no. of mole = 1.67 x 10²⁵/ 6.022 x 10²³ (molecules/mol)

          no. of mole = 27.7 moles

So,

moles of CaCO₃ = 27.7 moles

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.