Question

how many number of carbon atoms are present in 250 gram of caco3

Answer 1

Molar mass of CaCO₃ = 40 + 12 + 3×16 = 52 + 48 = 100u

No. of moles in CaCO₃ = Weight in g/Molecular weight

= 250/100

= 2.5 mol

1 molecule of CaCO₃ contains 1 atom of C

Or 1 mole of CaCO₃ contains 1 mole of C

Or 2.5 mole of CaCO₃ contains 2.5 mole of C

No. of atoms of C = 2.5 × 6.022 ×10²³ = 15.055 × 10²³ = 1.50 × 10²⁴ atoms

So, there are 1.50 × 10²⁴ atoms in 250 grams of CaCO₃

Answer 2

We have to find the number of Carbon atoms present in 250 gram of CaCO₃.

Steps to find the number of Carbon atoms :

step 1 : find the number of moles of Calcium carbonate (CaCO₃).

no of moles of CaCO₃ = given mass/molecular mass of CaCO₃

= $\frac{250g}{100g.mol^{-1}}$

[ molecular mass of CaCO₃ is 100 g/mol ]

= 2.5 mol

step 2 : find number of moles of carbon atoms in CaCO₃.

we see, there is only one carbon atom in a molecule of calcium carbonate.

so the number of moles of Carbon atoms = number of moles of CaCO₃ = 2.5 mol

step 3 : now finally find number of carbon atoms.

∵ number of carbon atoms = number of moles of carbon atoms × Avogadro's number

= 2.5 × 6.023 × 10²³

= 15.0575 × 10²³

= 1.50575 × 10²⁴

Therefore the number of carbon atoms present in 250g of CaCO₃ is 1.50575 × 10²⁴.