Question

Total number of molecules in 10g of calcium carbonate

Answer 1

No. of moles = given mass of compound / Molar mass

Given mass = 10g

Molar mass = (40 + 12 + 3x16) =100g/mol

No of moles of CaCO3 = 10 / 100 =0.1 mol

According to Avogadro’s law –

1 mol of CaCO3 molecules contains 6.022 x 1023 CaCO3 molecules

Hence, 0.1 mol of CaCO3 molecules will contain 6.022 x 1023x 0.1 molecules

i.e. 0.6022 x 1023 or 6.022 x 1022 molecules